Depression

The tricyclics are used to treat depression. Nortriptyline is an active metabolite of Amitriptyline. Therapeutic drug levels are monitored to assist the physician assessing therapeutic response and to avoid toxicity.

Clinical Significance

Aripiprazole (Abilify®) is an atypical antipsychotic and antidepressant used in the treatment of schizophrenia, bipolar disorder, and clinical depression. The analysis of aripiprazole is used to monitor compliance with drug therapy.

Description: The C-Reactive Protein test is used to identify and/or monitor inflammation in patients.

Also Known As: CRP Test, Inflammation test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

Average Processing Time: 2 to 3 days

When is a C-Reactive Protein test ordered?

When a person's medical history and signs and symptoms indicate that they may have a significant bacterial infection, a CRP test may be recommended. When a newborn displays signs of infection or when a person has sepsis symptoms including fever, chills, and rapid breathing and heart rate, it may be ordered.

It's also commonly requested on a regular basis to check illnesses like rheumatoid arthritis and lupus, and it's routinely repeated to see if medication is working. This is especially effective for inflammation issues because CRP levels decrease as inflammation decreases.

What does a C-Reactive Protein blood test check for?

C-reactive protein is a protein produced by the liver and released into the bloodstream within a few hours following tissue injury, infection, or other inflammatory event. After trauma or a heart attack, with active or uncontrolled autoimmune illnesses, and with acute bacterial infections like sepsis, markedly higher levels are reported. CRP levels can rise by a thousand-fold in response to inflammatory diseases, and their elevation in the blood can occur before pain, fever, or other clinical signs. The test detects inflammation caused by acute situations or monitors disease activity in chronic diseases by measuring the level of CRP in the blood.

The CRP test is not a diagnostic tool, although it can tell a doctor if inflammation is occurring. This information can be combined with other indicators like signs and symptoms, a physical exam, and other tests to establish whether someone has an acute inflammatory disorder or is having a flare-up of a chronic inflammatory disease. The health care provider may next do additional tests and treatment.

This CRP test should not be confused with the hs-CRP test. These are two separate CRP tests, each of which measures a different range of CRP levels in the blood for different purposes.

Lab tests often ordered with a C-Reactive Protein test:

• Sed Rate (ESR)
• Procalcitonin
• ANA
• Rheumatoid Factor
• Complement

Conditions where a C-Reactive Protein test is recommended:

• Arthritis
• Autoimmune Disorders
• Pelvic Inflammatory Disease
• Inflammatory Bowel Disease
• Sepsis
• Vasculitis
• Systemic Lupus Erythematosus
• Meningitis and Encephalitis

Commonly Asked Questions:

How does my health care provider use a C-Reactive Protein test?

A health practitioner uses the C-reactive protein test to diagnose inflammation. CRP is an acute phase reactant, a protein produced by the liver and released into the bloodstream within a few hours following tissue injury, infection, or other inflammatory event. The CRP test is not a diagnostic test for any ailment, but it can be used in conjunction with other tests to determine whether a person has an acute or chronic inflammatory disorder.

CRP, for example, can be used to detect or track substantial inflammation in someone who is suspected of having an acute ailment like:

• Sepsis is a dangerous bacterial infection.
• An infection caused by a fungus
• Inflammation of the pelvis

People with chronic inflammatory diseases can use the CRP test to detect flare-ups and/or see if their medication is working. Here are a few examples:

• Inflammatory bowel disease
• Arthritis, which can take many forms.
• Autoimmune disorders, examples include lupus and vasculitis

CRP is occasionally requested in conjunction with an erythrocyte sedimentation rate, another inflammatory test. While the CRP test is not specific enough to diagnose an illness, it does serve as a broad marker for infection and inflammation, alerting doctors to the need for more testing and treatment. A variety of additional tests may be used to determine the source of inflammation, depending on the probable cause.

What do my C-Reactive Protein test results mean?

CRP levels in the blood are usually low.

CRP levels in the blood that are high or rising indicate the existence of inflammation, but they don't tell you where it is or what's causing it. A high CRP level can establish the presence of a severe bacterial infection in people who are suspected of having one. High levels of CRP in persons with chronic inflammatory disorders indicate a flare-up or that treatment isn't working.

When the CRP level rises and then falls, it indicates that the inflammation or infection is diminishing and/or responding to treatment.

Is there anything else I should know about C-Reactive Protein?

CRP levels can rise during pregnancy, as well as with the use of birth control tablets or hormone replacement therapy. Obese people have also been found to have higher CRP levels.

In the presence of inflammation, the erythrocyte sedimentation rate test will also rise; however, CRP rises first and then falls faster than the ESR.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

Description: A High Sensitivity C-Reactive Protein test is a blood test used to accurately detect lower concentrations of the protein C-Reactive Protein. This test is used to evaluate your risk of cardiovascular and heart disease and to check for inflammation and many other issues.

Also Known As: hsCRP Test, Cardiac CRP Test, high sensitivity C-reactive protein Test, CRP Test for heart disease.

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

Average Processing Time: 3 to 4 days

When is a hs-CRP test ordered?

There is currently no consensus on when to get an hs-CRP test. It may be beneficial for treatment purposes to order hs-CRP for those that have kidney disease, diabetes or inflammatory disorders.

It's possible that hs-CRP will be tested again to confirm that a person has persistently low levels of inflammation.

What does a hs-CRP blood test check for?

C-reactive protein is a protein found in the blood that rises in response to infection and inflammation, as well as after trauma, surgery, or a heart attack. As a result, it's one of numerous proteins referred to as acute phase reactants. The high-sensitivity CRP test detects low levels of inflammation in the blood, which are linked to an increased risk of developing cardiovascular disease.

According to the American Heart Association, CVD kills more people in the United States each year than any other cause. A number of risk factors have been related to the development of CVD, including family history, high cholesterol, high blood pressure, being overweight or diabetic, however a considerable number of people with few or no recognized risk factors will also acquire CVD. This has prompted researchers to investigate for new risk variables that could be causing CVD or could be used to identify lifestyle modifications and/or treatments that could lower a person's risk.

High-sensitivity CRP is one of an increasing number of cardiac risk markers that may be used to assess an individual's risk. According to certain research, monitoring CRP with a highly sensitive assay can assist identify the risk level for CVD in persons who appear to be healthy. CRP levels at the higher end of the reference range can be measured with this more sensitive test. Even when cholesterol levels are within an acceptable range, these normal but slightly elevated levels of CRP in otherwise healthy persons might indicate the future risk of a heart attack, sudden cardiac death, stroke, and peripheral artery disease.

Lab tests often ordered with a hs-CRP test:

• Complete Blood Count
• Lipid Panel
• Comprehensive Metabolic Panel
• Lp-Pla2
• Glucose

Conditions where a hs-CRP test is recommended:

• Heart Attack
• Heart Disease
• Cardiovascular Disease
• Stroke

How does my health care provider use a hs-CRP test?

A test for high-sensitivity C-reactive protein can be used to assess a person's risk of cardiovascular disease. It can be used in conjunction with a lipid profile or other cardiac risk markers, such as the lipoprotein-associated phospholipase A2 test, to provide further information regarding the risk of heart disease.

CRP is a protein that rises in the bloodstream as a result of inflammation. A continuous low level of inflammation, according to studies, plays a crucial role in atherosclerosis, the narrowing of blood vessels caused by the build-up of cholesterol and other lipids, which is typically linked to CVD. The hs-CRP test successfully detects low levels of C-reactive protein, indicating low but chronic inflammation, and so aids in predicting a person's risk of developing CVD.

Some specialists believe that high-sensitivity CRP is a good test for assessing CVD, heart attacks, and stroke risk, and that it can help in the evaluation process before a person gets one of these health problems. Some experts believe that combining a good marker for inflammation, such as hs-CRP, with a lipid profile is the best way to predict risk. This test has been recommended by several organizations for persons who are at a moderate risk of having a heart attack in the following ten years.

What does my hs-CRP test result mean?

Even when cholesterol levels are within an acceptable range, high levels of hs-CRP in otherwise healthy people have been found to predict an elevated risk of future heart attacks, strokes, sudden cardiac death, and/or peripheral arterial disease.

Higher hs-CRP concentrations indicate a higher risk of cardiovascular disease, while lower values indicate a lower risk. Individuals with hs-CRP values at the high end of the normal range are 1.5 to 4 times more likely than those with low levels of hs-CRP to have a heart attack.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

Description: A Vitamin D test is a blood test used to determine if you have a Vitamin D deficiency and to monitor Vitamin D levels if you are on supplementation.

Also Known As: Ergocalciferol Test, Vitamin D2 Test, Cholecalciferol Test, Vitamin D3 Test, Calcidiol Test, 25-hydroxyvitamin D Test, Calcifidiol Test, 25-hydroxy-vitamin D Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: Fasting preferred, but not required.

Average Processing Time: 4 to 5 days

When is a Vitamin D test ordered:

When calcium levels are inadequate and/or a person exhibits symptoms of vitamin D deficiency, such as rickets in children and bone weakening, softness, or fracture in adults, 25-hydroxyvitamin D is frequently ordered to rule out a vitamin D deficit.

When a person is suspected of having a vitamin D deficiency, the test may be requested. Vitamin D deficiency is more common in older folks, people who are institutionalized or homebound and/or have minimal sun exposure, people who are obese, have had gastric bypass surgery, and/or have fat malabsorption. People with darker skin and breastfed babies are also included in this category.

Before starting osteoporosis medication, 25-hydroxyvitamin D is frequently requested.

What does a Vitamin D blood test check for?

Vitamin D is a group of chemicals that are necessary for the healthy development and growth of teeth and bones. The level of vitamin D in the blood is determined by this test.

Vitamin D is tested in the blood in two forms: 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D. The primary form of vitamin D found in the blood is 25-hydroxyvitamin D, which is a relatively inactive precursor to the active hormone 1,25-dihydroxyvitamin D. 25-hydroxyvitamin D is routinely evaluated to assess and monitor vitamin D status in humans due to its longer half-life and higher concentration.

Endogenous vitamin D is created in the skin when exposed to sunshine, whereas exogenous vitamin D is taken through foods and supplements. Vitamin D2 and vitamin D3 have somewhat different molecular structures. Fortified foods, as well as most vitamin preparations and supplements, include the D2 form. The type of vitamin D3 produced by the body is also used in some supplements. When the liver and kidneys convert vitamin D2 and D3 into the active form, 1,25-dihydroxyvitamin D, they are equally effective.

Some tests may not differentiate between the D2 and D3 forms of vitamin D and just report the total result. Newer methods, on the other hand, may record D2 and D3 levels separately and then sum them up to get a total level.

Vitamin D's major function is to assist balance calcium, phosphorus, and magnesium levels in the blood. Vitamin D is necessary for bone growth and health; without it, bones become fragile, misshapen, and unable to mend themselves properly, leading to disorders such as rickets in children and osteomalacia in adults. Vitamin D has also been proven to influence the growth and differentiation of a variety of other tissues, as well as to aid in immune system regulation. Other illnesses, such as autoimmune and cancer, have been linked to vitamin D's other roles.

According to the Centers for Disease Control and Prevention, two-thirds of the US population has adequate vitamin D, while one-quarter is at risk of inadequate vitamin D and 8% is at risk of insufficiency, as defined by the Institute of Medicine's Dietary Reference Intake.

The elderly or obese, persons who don't receive enough sun exposure, people with darker skin, and people who take certain drugs for lengthy periods of time are all at risk of insufficiency. Adequate sun exposure is usually defined as two intervals of 5-20 minutes each week. Vitamin D can be obtained through dietary sources or supplements by people who do not get enough sun exposure.

This test has 3 Biomarkers

• Vitamin D Total which is a combined measurement of Vitamin D, 25-Oh, D2 and Vitamin 25-Oh, D3
• Vitamin D, 25-Oh, D2 which is a measurement of ergocalciferol Vitamin D, which is Vitamin D obtained through plant sources. 
• Vitamin D, 25-Oh, D3 which is a measurement of cholecalciferol Vitamin D, which is Vitamin D obtained through animal sources.

Lab tests often ordered with a Vitamin D test:

• Complete Blood Count
• CMP
• Iron and TIBC
• Calcium
• Phosphorus
• PTH
• Magnesium

Conditions where a Vitamin D test is recommended:

• Kidney Disease
• Osteoporosis
• Lymphoma
• Cystic Fibrosis
• Autoimmune Disorders
• Celiac Disease
• Malabsorption
• Malnutrition

Commonly Asked Questions:

How does my health care provider use a Vitamin D test?

Determine whether a deficit or excess of vitamin D is causing bone weakening, deformity, or improper calcium metabolism.

Because PTH is required for vitamin D activation, it can aid in diagnosing or monitoring problems with parathyroid gland function.

Because vitamin D is a fat-soluble vitamin that is absorbed from the intestine like a fat, it can help monitor the health of people with conditions that interfere with fat absorption, such as cystic fibrosis and Crohn's disease.

People who have had gastric bypass surgery and may not be able to absorb adequate vitamin D should be closely monitored.

When vitamin D, calcium, phosphorus, and/or magnesium supplementation is suggested, it can help assess the success of the treatment.

What do my Vitamin D results result mean?

Despite the fact that vitamin D techniques differ, most laboratories use the same reference intervals. Because toxicity is uncommon, researchers have focused on the lower limit and what cut-off for total 25-hydroxyvitamin D shortage implies.

A low blood level of 25-hydroxyvitamin D could indicate that a person isn't getting enough sunlight or dietary vitamin D to meet his or her body's needs, or that there's an issue with absorption from the intestines. Seizure medications, notably phenytoin, might occasionally interfere with the liver's generation of 25-hydroxyvitamin D.

Vitamin D insufficiency has been linked to an increased risk of some malignancies, immunological illnesses, and cardiovascular disease.

Excessive supplementation with vitamin pills or other nutritional supplements frequently results in a high level of 25-hydroxyvitamin D.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

Carnitine, LC/MS/MS Includes: Carnitine, Total; Carnitine, Free; Carnitine, Esters; Esterified/Free Ratio

 

Clinical Significance

Serum carnitine analysis is useful in the diagnosis and monitoring of patients with carnitine deficiency (either primary or secondary). Primary carnitine deficiency is an autosomal recessively inherited genetic condition that affects carnitine uptake by cells and tissues through a defect in the plasma membrane carnitine transporter. Secondary carnitine deficiency can be seen in some disease states or in patients on carnitine-poor diets, but is also seen in a number of metabolic disorders. In these disorders, carnitine complexes with the accumulated substrate of the blocked metabolic step, and the resulting acylcarnitine ester is excreted in the urine, leading to a depletion of carnitine in the patient

Description: The celiac disease comprehensive panel test screens for antibodies associated with celiac disease in your blood’s serum.

Specimens from children less than 4 years of age (i.e., less than 48 months) are not appropriate for this test. The test for children 4 years of age and younger is the Celiac Disease Comprehensive Panel, Infant (test code 15981).

Also Known As: Anti-Tissue Transglutaminase Antibody test, tTG Test, tTGA Test, Endomysial Antibody Test, EMA Test, DGP Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

Average Processing Time: 4 to 5 days

IMPORTANT - Note this is Reflex Test which if additional tests are run you will be charged for the specific tests that the lab peforms. Additional test will be run if the following criteria are met.
If the Tissue Transglutaminase IgA is positive,

1. Endomysial Antibody Screen (IgA) will be performed at an additional charge (CPT code(s): 86255).
2. If the Endomysial Antibody Screen (IgA) is positive, Endomysial Antibody Titer will be performed at an additional charge (CPT code(s): 86256).
3. If the Total IgA is less than the lower limit of the reference range, based on age, Tissue Transglutaminase IgG will be performed at an additional charge (CPT code(s): 83516).

When is a Comprehensive Celiac Disease Panel test ordered?

Celiac disease tests are requested when signs and symptoms of celiac disease, malnutrition, and/or malabsorption are present. The condition is difficult to diagnose because the symptoms are typically ambiguous and varied. The symptoms may be faint at first and go unrecognized, but they will gradually worsen or appear irregularly. The illness can affect several sections of the body.

When somebody with celiac disease has been on a gluten-free regimen for a while, one or more antibody tests may be required. This is done to ensure that antibody levels have dropped and that the diet has been successful in reversing the damage to the gut lining.

Asymptomatic people may be examined if they have a close family with celiac disease, such as a parent or sibling, but celiac disease testing is not suggested as a general population screening at this time.

What does a Comprehensive Celiac Disease Panel blood test check for?

Celiac disease is an autoimmune condition marked by an abnormal immune response to gluten, a protein present in wheat and related grains such as rye and barley. Antibodies to celiac disease have been created to aid in the diagnosis and monitoring of the disease as well as a few other gluten-sensitive disorders. These tests look for autoantibodies in the blood, which are produced by the body as part of the immune response.

The small intestine is inflamed, and the villi that line the intestinal wall are damaged and destroyed as a result of the immunological response. The villi are tiny tissue folds that enhance the surface area of the intestine, allowing nutrients, vitamins, minerals, fluids, and electrolytes to be absorbed. When a gluten-sensitive person is exposed to gluten, the body releases autoantibodies that attack intestinal villi constituents. When villi are damaged or eliminated, the body's ability to absorb food is greatly reduced, and signs of malnutrition and malabsorption appear.

Celiac disease was previously only diagnosed by examining a tissue biopsy of the small intestine. The emergence of less invasive blood tests to check for celiac disease has lowered the amount of biopsies required.

The level of certain autoantibodies in the blood is measured in Celiac disease blood tests. There are tests to detect the IgA and IgG classes of autoantibodies, but the ones that assess IgA are more specific and are virtually solely utilized. IgG and IgA are two of five antibody protein classes produced by the immune system in reaction to a perceived danger. In gastrointestinal secretions, IgA is the most common antibody.

If a person has an IgA deficit, autoantibody testing for IgG may be ordered. This happens roughly 3% of the time in celiac disease patients and can result in false-negative test findings.

Celiac disease tests include:

• IgA anti-tissue transglutaminase antibody detects antibodies to tissue transglutaminase, an enzyme that induces protein crosslinking. The most sensitive and specific blood test for celiac disease is anti-tTG, IgA. People with an IgA deficiency may be prescribed anti-tTG from the IgG class.
• Quantitative immunoglobulin A: determines if someone is deficient in the IgA class of antibodies by measuring the total amount of IgA in their blood.
• Anti-DGP IgA antibodies are detected by deamidated gliadin peptide antibodies, IgA; like anti-tTG, the IgG class can be used to diagnose an IgA deficit.

Lab tests often ordered with a Comprehensive Celiac Disease Panel test:

• Immunoglobulin A
• Immunoglobulin G
• Fecal globulin
• Total Protein
• Albumin
• Calcium
• Iron Total
• Iron and Total Iron Binding Capacity
• Ferritin
• Vitamin B12
• Vitamin D
• Comprehensive Metabolic Panel (CMP)
• Complete Blood Count (CBC)
• Antibody Testing
• ANA Screen
• Sed Rate
• C-Reactive Protein
• F-Actin

Conditions where a Comprehensive Celiac Disease Panel test is recommended:

• Celiac Diseae
• Autoimmune Disorders
• Malabsorption
• Malnutrition
• Osteoporosis
• Lactose Intolerance
• Iron Deficiency Anemia
• Inflammatory Bowel Disease

How does my health care provider use a Comprehensive Celiac Disease Panel test?

Celiac disease antibody tests are used to diagnose and monitor celiac disease, an autoimmune condition caused by an abnormal immune response to gluten, a protein found in wheat and related food proteins found in rye and barley. Celiac disease tests are typically recommended for persons who have symptoms including anemia and gastrointestinal pain.

Because about four to twelve percent of people with close relatives that have celiac disease have or will develop celiac disease themselves, celiac testing may be used to screen for asymptomatic celiac disease. Those with other autoimmune illnesses may also be subjected to testing.

The number of certain antibodies in the blood is measured in Celiac disease blood tests. The following are the most common tests:

• The primary test ordered to screen for celiac disease is tissue transglutaminase antibody, IgA class. According to the American College of Gastroenterology's 2013 guidelines, it is the single test preferred by the American Gastroenterology Association and the American Gastroenterology Association for the identification of celiac disease in persons over the age of two years. If you have an IgA deficiency, you can obtain anti-tTG from the IgG class as an alternative. If the anti-tTG, IgA, or IgG test is positive, it can be used to monitor a person with celiac disease and assess treatment success; antibody levels should reduce as gluten is removed from the diet. Although these tests are called "tissue tests," they actually measure blood.
• Immunoglobulin quantification A test that is ordered in conjunction with, prior to, or after an anti-tTG test to detect IgA deficiency, which occurs in about 2-3 percent of celiac disease patients and can result in false-negative test results. If a person has an IgA deficit, a test for autoantibodies of the IgG class may be ordered.
• Antibodies to deamidated gliadin peptides, IgA or IgG, may be positive in certain celiac disease patients who are negative for anti-tTG, particularly children under the age of two. It's sometimes ordered in conjunction with or after an anti-tTG test, especially if the latter is negative. The American College of Gastroenterology recommends DGP IgG testing in addition to anti-tTG IgG testing for persons with low IgA or IgA deficiency. If the anti-DGP test is positive, celiac disease can be monitored.

Less frequently used tests include:

• Anti-endomysial antibodies – antibodies produced in response to continuing injury to the intestinal lining; tTg was discovered to be the chemical detected in this test. Anti-EMA antibodies of the IgA class are found in nearly 100% of persons with active celiac disease and 70% of people with dermatitis herpetiformis. Because the test is more difficult to perform and interpret than anti-tTg, it is utilized less frequently.
• Anti-reticulin antibody test — not as specific or sensitive as the other autoantibodies; it's identified in roughly 60% of celiac disease patients and 25% of dermatitis herpetiformis patients; it's rarely requested.
• A biopsy of the small intestine is used to confirm a diagnosis of celiac disease by looking for damage to the intestinal villi. Due to the invasive nature and high expense of a biopsy, antibody tests are frequently used to identify persons with a high risk of celiac disease.

Other tests may be conducted to establish the severity of the disease and the extent of any consequences that may occur, such as malnutrition, malabsorption, and organ involvement. Examples of tests include:

• Anti-F-actin — A positive result may suggest greater intestine damage if a person has been diagnosed with celiac disease and a health practitioner wants to assess the severity of intestinal damage.
• CBC to rule out anemia
• ESR is used to assess inflammation.
• CRP is used to assess inflammation.
• CMP is used to check electrolyte, protein, and calcium levels, as well as the kidney and liver's health.
• Vitamin D, B12, and folate are used to assess vitamin deficiency.
• To detect iron shortage, doctors use iron, iron binding capacity, or transferrin, and ferritin.
• Stool fat is used to assess malabsorption.

Because celiac disease patients may also have lactose intolerance, celiac disease testing may be combined with other intolerance and allergy testing.

What do my Celiac Disease panel test results mean?

An intestinal biopsy is usually performed after all positive and ambiguous celiac disease testing. Celiac disease is diagnosed definitively with a biopsy.

When a person with celiac disease avoids gluten from his or her diet, autoantibody levels should decrease. If they don't go down and the symptoms don't go away, there could be hidden gluten in the diet that hasn't been eliminated, or the person could have one of the uncommon kinds of celiac disease that is resistant to dietary adjustments. Rising levels of autoantibodies suggest noncompliance with a gluten-free diet when celiac disease tests are used to track progress.

Celiac disease tests may be negative if the person being tested has not consumed gluten for several weeks to months prior to the test. If the doctor suspects celiac disease, he or she may administer a gluten challenge, which involves introducing gluten into the patient's diet for several weeks or months to see if symptoms reappear. Celiac disease tests may be redone at that time, or a biopsy may be performed to look for damage to the villi in the intestine.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

The Digestive Health - Advanced contains the following tests

• C-Reactive Protein (CRP) 
• CBC (includes Differential and Platelets) 
• Comprehensive Metabolic Panel (CMP)
• Fecal Globin by Immunochemistry (InSure®) 
• Ferritin
• Folate, Serum
• Iron and Total Iron Binding Capacity (TIBC)
• QuestAssureD™ 25-Hydroxyvitamin D (D2, D3), LC/MS/MS 
• Transferrin
• Vitamin B12 (Cobalamin) 
• Celiac Disease Comprehensive Panel (w/ Reflexes)

Specimens from children less than 4 years of age (i.e., less than 48 months) are not appropriate for this test. The test for children 4 years of age and younger is the Celiac Disease Comprehensive Panel, Infant (test code 15981).

Includes

Tissue Transglutaminase, IgA with Reflexes; Total IgA with Reflex

IMPORTANT - Note this is Reflex Test which if additional tests are run you will be charged for the specific tests that the lab peforms. Additional test will be run if the following criteria are met.

If the Tissue Transglutaminase IgA is positive, 

1. Endomysial Antibody Screen (IgA) will be performed at an additional charge (CPT code(s): 86255).

If the Endomysial Antibody Screen (IgA) is positive, 

2. Endomysial Antibody Titer will be performed at an additional charge (CPT code(s): 86256).

If the Total IgA is less than the lower limit of the reference range, based on age, 

3. Tissue Transglutaminase IgG will be performed at an additional charge (CPT code(s): 83516).

Clinical Significance

Celiac disease is caused by an immune response to gluten in genetically sensitive individuals. The diagnosis is largely based on a biopsy of the small intestine, but serologic tests also help support a diagnosis and may assist identification of patients who may require biopsy.

Tissue transglutaminase antibodies (tTG, IgA) is a marker with 95% sensitivity and specificity. Total IgA is measured because 2-3% of celiac disease patients are IgA deficient. Because tTG, IgA, and anti-Gliadin IgA tend to decrease in patients on a gluten-free diet, these markers are also used to assess dietary compliance.

The endomysial antibody (EMA, IgA) assay has high specificity for celiac disease and is used to confirm positive anti-tTG results.

Digestive Health - Basic contains the following tests

• CBC (includes Differential and Platelets) 
• Comprehensive Metabolic Panel (CMP)
• Fecal Globin by Immunochemistry (InSure®) 
• Celiac Disease Comprehensive Panel (w/ Reflexes)

Specimens from children less than 4 years of age (i.e., less than 48 months) are not appropriate for this test. The test for children 4 years of age and younger is the Celiac Disease Comprehensive Panel, Infant (test code 15981).

Includes

Tissue Transglutaminase, IgA with Reflexes; Total IgA with Reflex

IMPORTANT - Note this is Reflex Test which if additional tests are run you will be charged for the specific tests that the lab peforms. Additional test will be run if the following criteria are met.

If the Tissue Transglutaminase IgA is positive, 

1. Endomysial Antibody Screen (IgA) will be performed at an additional charge (CPT code(s): 86255).

If the Endomysial Antibody Screen (IgA) is positive, 

2. Endomysial Antibody Titer will be performed at an additional charge (CPT code(s): 86256).

If the Total IgA is less than the lower limit of the reference range, based on age, 

3. Tissue Transglutaminase IgG will be performed at an additional charge (CPT code(s): 83516).

Clinical Significance

Celiac disease is caused by an immune response to gluten in genetically sensitive individuals. The diagnosis is largely based on a biopsy of the small intestine, but serologic tests also help support a diagnosis and may assist identification of patients who may require biopsy.

Tissue transglutaminase antibodies (tTG, IgA) is a marker with 95% sensitivity and specificity. Total IgA is measured because 2-3% of celiac disease patients are IgA deficient. Because tTG, IgA, and anti-Gliadin IgA tend to decrease in patients on a gluten-free diet, these markers are also used to assess dietary compliance.

The endomysial antibody (EMA, IgA) assay has high specificity for celiac disease and is used to confirm positive anti-tTG results.

Digestive Health - Basic Plus contains the followwing tests: 

• C-Reactive Protein (CRP) 
• CBC (includes Differential and Platelets) 
• Comprehensive Metabolic Panel (CMP)
• Fecal Globin by Immunochemistry (InSure®) 
• Ferritin
• Iron and Total Iron Binding Capacity (TIBC)
• Celiac Disease Comprehensive Panel (w/ Reflexes)

 Specimens from children less than 4 years of age (i.e., less than 48 months) are not appropriate for this test. The test for children 4 years of age and younger is the Celiac Disease Comprehensive Panel, Infant (test code 15981).

Includes

Tissue Transglutaminase, IgA with Reflexes; Total IgA with Reflex

IMPORTANT - Note this is Reflex Test which if additional tests are run you will be charged for the specific tests that the lab peforms. Additional test will be run if the following criteria are met.

If the Tissue Transglutaminase IgA is positive, 

1. Endomysial Antibody Screen (IgA) will be performed at an additional charge (CPT code(s): 86255).

If the Endomysial Antibody Screen (IgA) is positive, 

2. Endomysial Antibody Titer will be performed at an additional charge (CPT code(s): 86256).

If the Total IgA is less than the lower limit of the reference range, based on age, 

3. Tissue Transglutaminase IgG will be performed at an additional charge (CPT code(s): 83516).

Clinical Significance

Celiac disease is caused by an immune response to gluten in genetically sensitive individuals. The diagnosis is largely based on a biopsy of the small intestine, but serologic tests also help support a diagnosis and may assist identification of patients who may require biopsy.

Tissue transglutaminase antibodies (tTG, IgA) is a marker with 95% sensitivity and specificity. Total IgA is measured because 2-3% of celiac disease patients are IgA deficient. Because tTG, IgA, and anti-Gliadin IgA tend to decrease in patients on a gluten-free diet, these markers are also used to assess dietary compliance.

The endomysial antibody (EMA, IgA) assay has high specificity for celiac disease and is used to confirm positive anti-tTG results.

Digestive Health - Comprehensive contains the following tests: 

• C-Reactive Protein (CRP) 
• CBC (includes Differential and Platelets) 
• Comprehensive Metabolic Panel (CMP)
• Fecal Globin by Immunochemistry (InSure®) 
• Ferritin
• Folate, Serum
• Gliadin (Deamidated Peptide) Antibody (IgA) 
• Gliadin (Deamidated Peptide) Antibody (IgG) 
• Iron and Total Iron Binding Capacity (TIBC)
• Lipid Panel with Ratios
• Magnesium
• Prealbumin 
• QuestAssureD™ 25-Hydroxyvitamin D (D2, D3), LC/MS/MS 
• Transferrin
• TSH
• Vitamin A (Retinol)
• Vitamin B12 (Cobalamin) 
• Vitamin K
• Celiac Disease Comprehensive Panel (w/ Reflexes)

Specimens from children less than 4 years of age (i.e., less than 48 months) are not appropriate for this test. The test for children 4 years of age and younger is the Celiac Disease Comprehensive Panel, Infant (test code 15981).

Includes

Tissue Transglutaminase, IgA with Reflexes; Total IgA with Reflex

IMPORTANT - Note this is Reflex Test which if additional tests are run you will be charged for the specific tests that the lab peforms. Additional test will be run if the following criteria are met.

If the Tissue Transglutaminase IgA is positive, 

1. Endomysial Antibody Screen (IgA) will be performed at an additional charge (CPT code(s): 86255).

If the Endomysial Antibody Screen (IgA) is positive, 

2. Endomysial Antibody Titer will be performed at an additional charge (CPT code(s): 86256).

If the Total IgA is less than the lower limit of the reference range, based on age, 

3. Tissue Transglutaminase IgG will be performed at an additional charge (CPT code(s): 83516).

Clinical Significance

Celiac disease is caused by an immune response to gluten in genetically sensitive individuals. The diagnosis is largely based on a biopsy of the small intestine, but serologic tests also help support a diagnosis and may assist identification of patients who may require biopsy.

Tissue transglutaminase antibodies (tTG, IgA) is a marker with 95% sensitivity and specificity. Total IgA is measured because 2-3% of celiac disease patients are IgA deficient. Because tTG, IgA, and anti-Gliadin IgA tend to decrease in patients on a gluten-free diet, these markers are also used to assess dietary compliance.

The endomysial antibody (EMA, IgA) assay has high specificity for celiac disease and is used to confirm positive anti-tTG results.

Description: Estradiol is a blood test that is used to measure the levels of Estradiol in the blood's serum. Estradiol is one of the Estrogen hormones in the body.  Estradiol, Ultrasensitive LC/MS/MS #30289 is a more appropriate test for children that have not yet started a menstrual cycle.

Also Known As: E2 Test, Estrogen 2 Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

Average Processing Time: 1 to 2 days

When is an Estradiol test ordered?

Tests for estradiol for women may be ordered if:

• After menopause, a woman may experience symptoms such as abnormal vaginal bleeding or irregular or absent menstrual cycles.
• When a woman is unable to conceive, a series of estradiol readings taken over the course of her menstrual cycle may be used to track follicle development before using in vitro fertilization procedures
• A woman is experiencing menopause symptoms such as hot flashes, night sweats, sleeplessness, and/or irregular or absent menstrual cycles.
• If a menopausal woman is on hormone replacement therapy, her doctor may order estrone levels on a regular basis to check her progress.

Men and young boys may be subjected to estradiol testing if:

• A boy's puberty is delayed, as evidenced by slow or delayed growth of testicles and penis, as well as a lack of deepening of voice or growth of body hair.
• Signs of feminization, such as larger breasts.

What does an Estradiol blood test check for?

Estradiol, or E2, is a component of Estrogen that is present in the blood. For women, Estradiol is something that should be produced naturally, and the body produces larger amounts of Estradiol during puberty and it fluctuates throughout the menstrual cycle. Estradiol is most prominent in women of reproductive age. Low levels are common in girls who have not yet had their first menstrual cycle and in women after their reproductive age.

Lab tests often ordered with an Estradiol test:

• Estrogen, Total, Serum
• Estriol
• Estrone
• Testosterone Free and Total
• Sex Hormone Binding Globulin
• FSH
• LH
• Progesterone

Conditions where an Estradiol test is recommended:

• Infertility
• Menopause
• Polycystic Ovarian Syndrome
• Hormone Imbalance
• Premature, delayed, or abnormal development of sex organs

Commonly Asked Questions:

How does my health care provider use an Estradiol test?

Estrogen tests are used to detect a deficit or excess of estrogen in a woman, as well as to aid in the diagnosis of a range of illnesses linked to this imbalance. They may also be ordered to monitor the health of the growing fetus and placenta during pregnancy, as well as to help predict the timing of a woman's ovulation. Estrogen testing can be used to detect a hormone excess and its origin in men.

In the case of girls and women

Estradiol testing may be requested for the following reasons:

• Diagnose early-onset puberty, which occurs when a girl develops secondary sex traits much earlier than anticipated, or late puberty, which occurs when a female develops secondary sex characteristics or begins menstruation later than predicted.
• Examine menstrual irregularities such as the absence of menstrual periods, infertility, and unusual vaginal bleeding.
• Evaluate ovary function and look for signs of ovarian failure.
• Serial measurements of estradiol can be used to track follicle development in the ovary in the days leading up to in vitro fertilization.
• Keep track of any hormone replacement therapy you're getting to help with your fertility.
• Keep track of menopausal hormone replacement medication, which is used to treat symptoms caused by estrogen insufficiency.
• Identify cancers that produce estrogen.
• As with breast cancer, keep an eye on anti-estrogen therapy.

Boys and men may be subjected to estradiol testing in order to:

• Assist in the diagnosis of delayed puberty
• Assist in determining the cause of larger breasts or other feminization indications.
• Detect an excess of relative estrogen due to a testosterone or androgen deficit.
• Identify cancers that produce estrogen.

What do my Estradiol test results mean?

Estradiol is one of the three Estrogens that have a large impact on the women's body throughout the menstrual cycle. When these hormones are too high or too low, it could cause irregular bleeding, infertility, complications with menopause, and delayed or premature puberty. Out of range levels can also be indicative of an ovarian condition such as PCOS. It is important to note that these values will fluctuate throughout a woman's cycle. The Estrogen hormones work together and if one is out of range, the others may also be out of range. It is recommended to follow up with a licensed healthcare professional to determine the best treatment if need.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

IMPORTANT - Note this Estradiol test is not for children that have yet to start their menstrual cycle.  If this test is ordered for a child that has yet to begin their menstrual cycle Quest Diagnostics labs will substitute in Estradiol, Ultrasensitive LC/MS/MS - #30289 at an additional charge of $34

Description: A Glucose test is a blood test used to screen for, diagnose, and monitor conditions that affect glucose levels such as prediabetes, diabetes, hyperglycemia, and hypoglycemia.

Also Known As: Fasting Blood Glucose Test, FBG Test, Fasting Blood Sugar Test, FBS Test, Fasting Glucose Test, FG Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: Fasting required

Average Processing Time: 1 to 2 days

When is a Glucose test ordered?

Diabetes screening is recommended by several health groups, including the American Diabetes Association and the United States Preventive Services Task Force, when a person is 45 years old or has risk factors.

The ADA recommends retesting within three years if the screening test result is within normal limits, but the USPSTF recommends testing once a year. Annual testing may be used to monitor people with prediabetes.

When someone exhibits signs and symptoms of high blood glucose, a blood glucose test may be conducted.

Diabetics are frequently asked to self-check their glucose levels multiple times a day in order to monitor glucose levels and choose treatment alternatives as suggested by their doctor. Blood glucose levels may be ordered on a regular basis, along with other tests such as A1c, to track glucose control over time.

Unless they show early symptoms or have had gestational diabetes in a prior pregnancy, pregnant women are routinely screened for gestational diabetes between the 24th and 28th week of pregnancy. If a woman is at risk of type 2 diabetes, she may be tested early in her pregnancy, according to the American Diabetes Association. When a woman has type 1, type 2, or gestational diabetes, her health care provider will normally order glucose levels to monitor her condition throughout the duration of her pregnancy and after delivery.

What does a Glucose blood test check for?

A fasting glucose test measures glucose. Glucose is the major energy source for the body's cells and the brain and nervous system's only source of energy. A consistent supply must be provided, and a somewhat constant level of glucose in the blood must be maintained. The glucose level in the blood can be measured using a variety of methods. 

Fruits, vegetables, breads, and other carbohydrate-rich foods are broken down into glucose during digestion, which is absorbed by the small intestine and circulated throughout the body. Insulin, a hormone generated by the pancreas, is required for the use of glucose for energy production. Insulin promotes glucose transport into cells and instructs the liver to store surplus energy as glycogen for short-term storage or triglycerides in adipose cells.

Normally, blood glucose rises slightly after you eat or drink, and the pancreas responds by releasing insulin into the blood, the amount of which is proportional to the size and substance of the meal. The level of glucose in the blood declines as glucose enters the cells and is digested, and the pancreas responds by delaying, then ceasing the secretion of insulin.

When blood glucose levels fall too low, such as between meals or after a strong activity, glucagon is released, which causes the liver to convert some glycogen back into glucose, so boosting blood glucose levels. The level of glucose in the blood remains pretty steady if the glucose/insulin feedback loop is working appropriately. When the balance is upset and the blood glucose level rises, the body strives to restore it by boosting insulin production and removing excess glucose through the urine.

Several diseases can cause the equilibrium between glucose and pancreatic hormones to be disrupted, resulting in high or low blood glucose. Diabetes is the most common cause. Diabetes is a collection of illnesses characterized by inadequate insulin production and/or insulin resistance. Untreated diabetes impairs a person's ability to digest and utilize glucose normally. Type 1 diabetes is diagnosed when the body is unable to produce any or enough insulin. People with prediabetes or type 2 diabetes are insulin resistant and may or may not be able to produce enough of the hormone.

Organ failure, brain damage, coma, and, in extreme situations, death can result from severe, sudden fluctuations in blood glucose, either high or low. Chronically high blood glucose levels can harm body organs like the kidneys, eyes, heart, blood vessels, and nerves over time. Hypoglycemia can harm the brain and nerves over time.

Gestational diabetes, or hyperglycemia that exclusively arises during pregnancy, can affect some women. If left untreated, this can result in large babies with low glucose levels being born to these mothers. Women with gestational diabetes may or may not acquire diabetes later in life.

Lab tests often ordered with a Glucose test:

• Complete Blood Count
• Iron Total and Total Iron binding capacity
• Hemoglobin A1c
• Lipid Panel
• Urinalysis Complete
• TSH
• CMP
• Insulin
• Microalbumin
• Fructosamine
• C-Peptide

Conditions where a Glucose test is recommended:

• Diabetes
• Kidney Disease
• Insulin Resistance
• Pancreatic Diseases
• Hyperglycemia
• Hypoglycemia

Commonly Asked Questions:

How does my health care provider use a Glucose test?

The blood glucose test can be used for a variety of purposes, including:

• Detect hyperglycemia and hypoglycemia
• Screen for diabetes in those who are at risk before symptoms appear; there may be no early indications or symptoms of diabetes in some circumstances. As a result, screening can aid in detecting it and allowing treatment to begin before the illness worsens or complications emerge.
• Aid in the detection of diabetes, prediabetes, and gestational diabetes.
• Monitor your blood sugar levels and manage your diabetes

Glucose levels should be monitored in those who have been diagnosed with diabetes.

Between the 24th and 28th week of pregnancy, glucose blood tests are performed to assess pregnant women for gestational diabetes. Pregnant women who have never been diagnosed with diabetes should be screened and diagnosed using either a one-step or two-step strategy, according to the American Diabetes Association and the US Preventive Services Task Force.

Other tests, including diabetic autoantibodies, insulin, and C-peptide, may be used in conjunction with glucose to assist in detecting the reason of elevated glucose levels, differentiate between type 1 and type 2 diabetes, and assess insulin production.

What does my glucose test result mean?

High blood glucose levels are most commonly associated with diabetes, but they can also be caused by a variety of other diseases and ailments.

Hypoglycemia is defined by a drop in blood glucose to a level that triggers nervous system symptoms before affecting the brain. The Whipple triad is a set of three criteria for diagnosing hypoglycemia.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

Description: Hemoglobin A1c is the protein Hemoglobin found in red blood cells, but with glucose attached to it. Hemoglobin A1c is used to check for and monitor diabetes as it shows average blood glucose levels over the past 2 to 3 months.

Also Known As: A1c Test, HbA1c Test, Glycohemoglobin Test, Glycated Hemoglobin Test, Glycosylated Hemoglobin Test, HbA1c Test

Collection Method: Blood Draw

Specimen Type: Whole Blood

Test Preparation: No preparation required

Average Processing Time: 1 to 2 days

When is a Hemoglobin A1c test ordered?

A1c may be requested as part of a routine physical examination or when a practitioner suspects a patient of having diabetes due to characteristic signs or symptoms of high blood sugar, such as:

• Increased thirst and fluid intake
• Increased urination
• Increase in hunger
• Fatigue
• Vision is hazy
• Infections that take a long time to heal

Adults who are overweight and have the following additional risk factors may consider doing the A1c test:

• Physically inactive
• Diabetes in a first-degree relative
• Race/ethnicity that is at high risk such as African Americans, Latinos, Native Americans, Asian Americans, and Pacific Islanders
• Blood pressure that is high
• A lipid profile that is abnormal.
• Polycystic ovarian syndrome 
• Cardiovascular disease 
• Insulin resistance and other conditions links to insulin resistance

People who have not been diagnosed with diabetes but have been assessed to be at an increased risk of developing diabetes should have their A1c levels tested at least once a year.

Monitoring

The A1c test may be performed 2 to 4 times a year, depending on the type of diabetes a person has, how well their diabetes is controlled, and the healthcare provider's recommendations. If diabetics are fulfilling treatment goals and have stable glycemic control, the American Diabetes Association advises A1c testing at least twice a year. A1c may be ordered quarterly when someone is first diagnosed with diabetes or if control isn't good.

What does a Hemoglobin A1c blood test check for?

Hemoglobin A1c, often known as A1c or glycated hemoglobin, is hemoglobin that has been attached to glucose. By assessing the proportion of glycated hemoglobin, the A1c test determines the average quantity of glucose in the blood during the previous 2 to 3 months.

Hemoglobin is a protein present inside red blood cells that transports oxygen.

Glycated hemoglobin is generated in proportion to the amount of glucose in the blood. Once glucose attaches to hemoglobin, it stays there for the duration of the red blood cell's life, which is usually about 120 days. The most common kind of glycated hemoglobin is known as A1c. A1c is created on a daily basis and is gradually removed from the bloodstream as older RBCs die and younger RBCs replace them.

This test can be used to detect and diagnose diabetes, as well as the risk of developing it. According to the American Diabetes Association's standards of medical care in diabetes, diabetes can be diagnosed using either A1c or glucose.

This test can also be used to track the progress of a diabetic patient's treatment. It aids in determining how well a person's glucose levels have been controlled over time by medication. An A1c of less than 7% suggests good glucose control and a lower risk of diabetic complications for the majority of diabetics for monitoring reasons.

Lab tests often ordered with a Hemoglobin A1c test:

• Complete Blood Count
• Glucose
• Frucstosamine
• Albumin
• Comprehensive Metabolic Panel
• Microalbumin w/creatinine
• Lipid panel

Conditions where a Hemoglobin A1c test is recommended:

• Type 1 Diabetes
• Type 2 Diabetes

How does my health care provider use a Hemoglobin A1c test?

Adults can use the hemoglobin A1c test to screen for and diagnose diabetes and prediabetes.

A fasting glucose or oral glucose tolerance test should be done to screen or diagnose diabetes in these instances.

The A1c test is also used to track diabetics' glucose control over time. Diabetics strive to maintain blood glucose levels that are as close to normal as feasible. This helps to reduce the risks of consequences associated with chronically high blood sugar levels, such as progressive damage to body organs such as the kidneys, eyes, cardiovascular system, and nerves. The result of the A1c test depicts the average quantity of glucose in the blood over the previous 2-3 months. This can help diabetics and their healthcare professionals determine whether the steps they're taking to control their diabetes are working or if they need to be tweaked.

A1c is a blood test that is usually used to help newly diagnosed diabetics identify how high their uncontrolled blood glucose levels have been in the previous 2-3 months. The test may be ordered multiple times throughout the control period, and then at least twice a year after that to ensure that good control is maintained.

What does my Hemoglobin A1c test result mean?

HbA1c levels is currently reported as a percentage for monitoring glucose control, and it is suggested that most diabetics try to keep their hemoglobin A1c below 7%. The closer diabetics can keep their A1c to the therapeutic objective of less than 7% without experiencing abnormally low blood glucose, the better their diabetes is controlled. The risk of problems rises as the A1c rises.

However, a person with type 2 diabetes may have an A1c goal set by their healthcare professional. The length of time since diagnosis, the presence of other diseases as well as diabetes complications, the risk of hypoglycemia complications, life expectancy, and whether or not the person has a support system and healthcare resources readily available are all factors that may influence the goal.

For example, a person with heart disease who has had type 2 diabetes for many years without diabetic complications may have a higher A1c target set by their healthcare provider, whereas someone who is otherwise healthy and newly diagnosed may have a lower target set by their healthcare provider as long as low blood sugar is not a significant risk.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

Description: Homocysteine is an amino acid that is present in every cell. There is a small amount present as it is an amino acid that changes quickly into other needed products in the body.

Also Known As: Homocysteine Cardiac Risk Test, Homocysteine Blood Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: Fasting for at least 8 hours is preferred

Average Processing Time: 2 to 3 days

When is a Homocysteine test ordered?

When a doctor feels a person may be deficient in vitamin B12 or folate, he or she may request this test. At first, the signs and symptoms are vague and ambiguous. People who have an early deficit may be diagnosed before they show any visible symptoms. Other persons who are impacted may experience a range of moderate to severe symptoms, including:

• Diarrhea
• Dizziness
• Weakness and exhaustion
• Appetite loss
• Paleness
• Heart rate that is quite fast
• Breathing problems
• Tongue and mouth ache
• In the feet, hands, arms, and legs, there is tingling, numbness, and/or burning

Depending on an individual's age and other risk factors, homocysteine may be requested as part of determining a person's risk of developing cardiovascular disease. It may also be ordered after a heart attack or stroke to aid in treatment planning.

When newborn screening identifies an increased level of methionine or if an infant or kid shows signs and symptoms of homocystinuria, this test may be ordered. Babies with this illness will appear normal at birth, but if left untreated, they will develop symptoms such as a displaced lens in the eye, a long slender build, long thin fingers, and skeletal abnormalities within a few years.

What does a Homocysteine blood test check for?

Homocysteine is an amino acid that is found in trace amounts in all of the body's cells. The body generally converts homocysteine to other compounds fast. Because vitamins B6, B12, and folate are required for homocysteine metabolism, elevated levels of the amino acid could indicate a vitamin deficit. The level of homocysteine in the blood is determined by this test.

Increased homocysteine levels have also been linked to an increased risk of coronary heart disease, stroke, peripheral vascular disease, and artery hardening. Homocysteine has been linked to cardiovascular disease risk through a variety of processes, including damage to blood vessel walls and support for the production of abnormal blood clots, but no direct linkages have been established. Several studies have also found no benefit or reduction in CVD risk with folic acid and B vitamin supplementation. The American Heart Association does not believe it to be a significant risk factor for heart disease at this time.

Homocysteine levels in the blood can also be dramatically increased by a rare genetic disorder known as homocystinuria. In homocystinuria, one of multiple genes is mutated, resulting in a defective enzyme that prevents the normal breakdown of methionine, the precursor of homocysteine. Methionine is one of the eleven necessary amino acids that the body cannot make and must therefore be obtained from food.

Homocysteine and methionine build up in the body without the necessary enzyme to break them down. Babies born with this condition appear normal at birth, but develop symptoms such as a long slender build, a dislocated lens in the eye, long thin fingers, osteoporosis, skeletal abnormalities, and a significantly increased risk of thromboembolism and atherosclerosis, which can lead to premature CVD within a few years.

In addition to intellectual disability, mental illness, a little low IQ, behavioral issues, and seizures, artery blockages can induce intellectual disability, mental illness, and seizures. Some of them can be avoided if homocystinuria is diagnosed early, which is why all states screen neonates for the disease.

Lab tests often ordered with a Homocysteine test:

• Vitamin B12
• Folate
• MTHFR Mutation
• Intrinsic Factor Antibody

Conditions where a Homocysteine test is recommended:

• Vitamin B12 and Folate Deficiency
• Heart Attack
• Heart Disease
• Stroke

How does my health care provider use a Homocysteine test?

The homocysteine test can be used in a variety of ways, including:

A homocysteine test may be ordered by a doctor to see if a person is deficient in vitamin B12 or folate. Before B12 and folate tests are abnormal, the homocysteine level may be raised. Homocysteine testing may be recommended by some health professionals in malnourished people, the elderly, who absorb less vitamin B12 from their diet, and people who have poor nutrition, such as drug or alcohol addicts.

For those at high risk of a stroke or heart attack, homocysteine testing may be requested as part of a health screening. It could be beneficial for someone who has a family history of coronary artery disease but no other recognized risk factors like smoking, high blood pressure, or obesity. However, because the specific role of homocysteine in the course of cardiovascular disease is unknown, the screening test's efficacy continues to be questioned.

If a health professional believes that an infant or kid has homocystinuria, tests for both urine and blood homocysteine can be utilized to assist diagnose the genetic condition. As part of their newborn screening in the United States, all babies are regularly tested for excess methionine, a symptom of homocystinuria. If a baby's test results are positive, urine and blood homocysteine tests are frequently used to confirm the results.

What do my homocysteine test results mean?

Homocysteine levels may be high in cases of suspected malnutrition, vitamin B12, or folate insufficiency. If a person does not consume enough B vitamins and/or folate through diet or supplements, the body may be unable to convert homocysteine into forms that the body can use. The level of homocysteine in the blood may rise in this scenario.

According to studies conducted in the mid- to late-1990s, those with high homocysteine levels have a substantially higher risk of heart attack or stroke than those with normal levels. The study of the relationship between excessive homocysteine levels and heart disease is still ongoing. However, considering that multiple trials studying folic acid and B vitamin supplementation have found no benefit or reduction in CVD risk, the use of homocysteine levels for risk assessment of cardiovascular disease, peripheral vascular disease, and stroke is now questionable.

A 2012 research study using various datasets, including 50,000 persons with coronary heart disease, called into question the possibility of a cause-and-effect relationship between homocysteine levels and heart disease. Although the American Heart Association recognizes a link between homocysteine levels and heart attack/stroke survival rates, it does not consider high homocysteine to be a major CVD risk factor.

While the AHA does not advocate for widespread use of folic acid and B vitamins to reduce the risk of heart attack and stroke, it does advocate for a balanced, nutritious diet and advises doctors to consider total risk factors as well as nutrition when treating cardiovascular disease.

Significantly elevated homocysteine concentrations in the urine and blood indicate that an infant is likely to have homocystinuria and need additional testing to confirm the reason of the increase.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

Imipramine is a tricyclic antidepressnt drug used to treat depression. Therapeutic drug monitoring is used to optimize dose and to avoid toxicity.

Brief Description: An Insulin test is a blood test that measures the insulin levels in the blood's serum. It is a measurement that is heavily used in patients with diabetes.

Also Known As: Fasting Insulin Test, Insulin Assay Test, Insulin Serum Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: 9 Hours Fasting Required

Average Processing Time: 2 to 3 days

When is an Insulin test ordered?

Insulin levels are most commonly ordered after a low glucose result or when someone has acute or chronic symptoms of hypoglycemia.  Hypoglycemia can cause the following symptoms:

• Sweating
• Palpitations
• Hunger
• Brain fog
• Hazy vision
• Dizziness
• Fainting

Seizures and loss of consciousness are common in severe instances.

While low blood glucose can cause these symptoms, they can also be caused by other illnesses.

When a person has or is suspected of having insulin resistance, an insulin test may be performed. People with type 2 diabetes, polycystic ovary syndrome, prediabetes or cardiac disease, or metabolic syndrome may fall into this category.

After an insulinoma has been effectively removed, a health practitioner may arrange insulin and C-peptide testing to verify the effectiveness of treatment and subsequently order the tests on a regular basis to monitor for recurrence.

Periodic testing can also be performed to track the success of an islet cell transplant by determining the graft's insulin-producing capacity.

What does an Insulin blood test check for?

Insulin is a hormone produced in the pancreas' beta cells and stored there. It is necessary for the transfer and storage of glucose, the body's primary energy source. Insulin aids in the delivery of glucose from the bloodstream to cells, as well as the regulation of blood glucose levels and lipid metabolism. This test determines how much insulin is present in the blood.

The levels of insulin and glucose in the blood must be balanced. Carbohydrates are frequently broken down into glucose and other simple sugars after a meal. The blood glucose level rises, prompting the pancreas to produce insulin into the bloodstream. The amount of glucose in the blood reduces as it enters cells, and the amount of insulin released by the pancreas decreases.

If an individual is unable to produce enough insulin, or if the body's cells become resistant to its effects, glucose is unable to reach the majority of the body's cells, causing the cells to starve as blood glucose climbs to harmful levels. This can disrupt normal metabolic processes, leading to a variety of illnesses and difficulties, such as kidney disease, cardiovascular disease, and eyesight and neurological issues.

Diabetes is a life-threatening illness characterized by excessive glucose levels and diminished insulin action. People with type 1 diabetes produce relatively little insulin, necessitating the use of insulin supplements. Insulin resistance is a common cause of type 2 diabetes, which worsens over time.

Insulin resistance occurs when the body is unable to respond to insulin's effects. The body makes up for this by manufacturing more of the hormone. Hyperinsulinemia and overstimulation of some insulin-sensitive tissues happen as a result of this. This process generates an imbalance in the connection between glucose and insulin over time, which, if left untreated, can lead to health problems affecting numerous regions of the body.

Insulin resistance can be present in people with polycystic ovary syndrome, prediabetes or cardiac disease, metabolic syndrome, and diseases of the pituitary or adrenal glands, in addition to type 2 diabetes.

Hyperinsulinemia is most commonly seen in persons with tumors of the pancreatic islet cells or an excess of injected insulin, aside from insulin resistance. Low blood sugar is caused by hyperinsulinemia, which can cause sweating, hunger, palpitations, confusion, dizziness, blurred vision, seizures, and fainting. Because the brain relies on blood glucose for energy, severe glucose deprivation caused by hyperinsulinemia can swiftly result in insulin shock and death.

Lab tests often ordered with an Insulin test:

• Glucose
• Hemoglobin A1c
• C-Peptide
• Comprehensive Metabolic Panel

Conditions where an Insulin test is recommended:

• Diabetes
• Insulin Resistance
• PCOS
• Metabolic Syndrome

Commonly Asked Questions:

How does my health care provider use an insulin test?

Insulin testing can be used for a variety of purposes. Insulin is a hormone produced in the pancreas' beta cells and stored there. Insulin is a hormone that aids in the movement of glucose, the body's primary source of energy, from the bloodstream to the cells. Cells starve if a person produces too little insulin or is resistant to its effects. When someone produces too much insulin, such as when they have an insulin-producing tumor, symptoms of low blood glucose appear.

Insulin testing may be used to assist with the following:

• Diagnose an insulinoma, confirm that the tumor was successfully removed, and/or keep an eye out for recurrence.
• Determine the source of hypoglycemia in a person who has signs and symptoms.
• Recognize insulin resistance.
• In this instance, a C-peptide test may be used to monitor the quantity of insulin produced by the beta cells in the pancreas. As part of the conversion of proinsulin to insulin in the pancreas, the body produces both insulin and C-peptide at the same time. When a doctor wishes to know how much insulin is created by the body and how much comes from outside sources like insulin injections, both tests may be ordered. The C-peptide test indicates insulin produced by the pancreas, but the insulin test analyzes insulin from both sources.
• Determine when a type 2 diabetic may need to supplement oral medications with insulin.

Insulin tests can be ordered in conjunction with glucose and C-peptide tests. In addition to the glucose tolerance test, insulin levels are sometimes employed. To assess insulin resistance, blood glucose and insulin levels are tested at pre-determined time intervals in this circumstance.

What do my Insulin test result mean?

Insulin levels must be reviewed in the context of other diagnostic tests and symptoms.

Insulin levels can be elevated with:

• Acromegaly
• Cushing's syndrome
• Use of medications such as corticosteroids, levodopa, and oral contraceptives
• Intolerance to fructose or galactose
• Insulinomas
• Obesity
• Insulin resistance, as seen in type 2 diabetes and metabolic syndrome

Insulin levels can be low with:

• Diabetes 
• Hypopituitarism
• Chronic pancreatitis 
• Pancreatic cancer

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

Description: The Lyme disease antibody test is testing for Borrelia antibodies. Borrelia is the bacteria that causes Lyme Disease. The immune system produces antibodies to fight against the infection of Borrelia, or Lyme disease.

Also Known As: Borrelia burgdorferi Test, Lyme Disease Antibodies IgG IgM Immunoblot Test, Lyme Disease antibodies Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

Average Processing Time: 2 to 3 days

When is a Lyme Disease Antibody test ordered?

When a person shows signs and symptoms of Borrelia infection and lives in or has visited a place where deer ticks, also known as black-legged ticks, are abundant, especially if the person has recently been bitten by a tick, Lyme disease testing is required.

Testing may be repeated after a few weeks if initial testing is negative but the suspicion of Lyme disease remains strong.

When a person does not have typical Lyme disease symptoms or a history of tick bites, and has not traveled to a Lyme disease-endemic area, a healthcare provider may rule out alternative possibilities before diagnosing and testing for Lyme disease.

What does a Lyme Disease Antibody blood test check for?

The bacteria Borrelia burgdorferi and Borrelia mayonii, which are transported predominantly by the deer tick, often known as the black-legged tick, cause Lyme disease. Borrelia antibodies in the blood are measured in Lyme disease tests.

The body's immune system produces these antibodies in reaction to exposure to Borrelia, the organism that causes Lyme disease. Infected deer ticks or black-legged ticks bite humans and transfer the bacterium. In areas where these ticks reside, such as the northeastern, mid-Atlantic, and midwestern United States, the disease is most common in the spring and summer.

A distinctive erythema migrans or "bulls-eye" rash that develops from the bite site, fever, chills, headache, and exhaustion are all indications of Lyme disease infection. Lyme disease can progress to cause intermittent joint pain and swelling, facial paralysis, weakening and numbness in the arms and legs, meningitis, memory issues, and in rare cases, heart and vision problems if left untreated.

It takes time for the immune system to produce antibodies against Borrelia. Two types of antibodies can be detected using laboratory tests. IgM antibodies are normally evident two to three weeks after the commencement of infection, while IgG antibodies are seen several weeks later.

Lab tests often ordered with a Lyme Disease Antibody test:

• Babesia Microti Antibodies
• Bartonella Species Antibodies
• Ehrlichia Chaffeensis Antibodies
• Epstein-Barr Virus Antibody Panel

Conditions where a Lyme Disease Antibody test is recommended:

• Lyme Disease

How does my health care provider use a Lyme Disease Antibody test?

Lyme disease tests are performed to see if a person has been infected with the germs Borrelia burgdorferi or Borrelia mayonii and has the symptoms of the disease. Antibodies generated by the immune system in response to infection are detected by the tests.

IgM and IgG antibodies can be detected via laboratory tests.

Antibodies to Borrelia IgM are frequently present in the blood two to three weeks after exposure. IgM concentrations peak about six weeks and then start to drop.

IgG antibodies are not detectable for many weeks after exposure, peak at four to six months, and can last for several years.

To identify these antibodies and confirm a diagnosis of Lyme disease, the Centers for Disease Control and Prevention recommends using two alternative procedures. The initial test is designed to be extremely sensitive in order to detect as many Lyme disease cases as possible. When a person does not have Lyme disease but does have another condition, such as another tick-borne disease, syphilis, or an autoimmune ailment like lupus, it may be positive. If the initial test yields a positive result, a second test using a different method is done to validate the findings. 

Lyme disease can be difficult to diagnose at times. If a person has removed a tick from his or her skin, has had a known tick bite, and lives in or has visited an area of the country where Lyme disease is common, the timing of the probable infection can be accurately predicted. However, because the tick is about the size of a pinhead, the bite may go unnoticed. Not everyone will get the rash, and the symptoms that do occur may be nonspecific and flu-like in the beginning, with joint pain that progresses to chronic arthritis and/or neurological problems that appear months later.

What do my Lyme Disease antibody test results mean?

Antibodies are not produced in a healthy adult who has never been infected with Borrelia germs.

If a person exhibits signs and symptoms, as well as positive EIA or IFA and western blot tests, it is likely that they have Lyme disease.

If a person tests positive for IgM antibody but negative for IgG and western blot, they may have had a recent infection or a false-positive test result.

If an IgM result is undetectable but the IgG and Western blot tests are positive, the person examined is likely to have a later stage infection or to have had an infection previously.

If all tests come out negative, the person's symptoms are either caused by something else or the antibody levels are too low to detect at that time; retesting in 2 to 3 weeks may be required to confirm or rule out infection.

If the IgM and western blot are negative but the IgG is positive, the person has either recovered from Lyme disease or the symptoms are due to cross reactive antibodies plus something else.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

Description: The Lyme disease antibody test is testing for Borrelia antibodies. Borrelia is the bacteria that causes Lyme Disease. The immune system produces antibodies to fight against the infection of Borrelia, or Lyme disease.

Also Known As: Borrelia burgdorferi Test, Lyme Disease Antibodies IgG IgM Immunoblot Test, Lyme Disease antibodies Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

Average Processing Time: 3 to 4 days

When is a Lyme Disease Antibodies test ordered?

When a person shows signs and symptoms of Borrelia infection and lives in or has visited a place where deer ticks, also known as black-legged ticks, are abundant, especially if the person has recently been bitten by a tick, Lyme disease testing is required.

Testing may be repeated after a few weeks if initial testing is negative but the suspicion of Lyme disease remains strong.

When a person does not have typical Lyme disease symptoms or a history of tick bites, and has not traveled to a Lyme disease-endemic area, a healthcare provider may rule out alternative possibilities before diagnosing and testing for Lyme disease.

What does a Lyme Disease Antibodies blood test check for?

The bacteria Borrelia burgdorferi and Borrelia mayonii, which are transported predominantly by the deer tick, often known as the black-legged tick, cause Lyme disease. Borrelia antibodies in the blood are measured in Lyme disease tests.

The body’s immune system produces these antibodies in reaction to exposure to Borrelia, the organism that causes Lyme disease. Infected deer ticks or black-legged ticks bite humans and transfer the bacterium. In areas where these ticks reside, such as the northeastern, mid-Atlantic, and midwestern United States, the disease is most common in the spring and summer.

A distinctive erythema migrans or “bulls-eye” rash that develops from the bite site, fever, chills, headache, and exhaustion are all indications of Lyme disease infection. Lyme disease can progress to cause intermittent joint pain and swelling, facial paralysis, weakening and numbness in the arms and legs, meningitis, memory issues, and in rare cases, heart and vision problems if left untreated.

It takes time for the immune system to produce antibodies against Borrelia. Two types of antibodies can be detected using laboratory tests. IgM antibodies are normally evident two to three weeks after the commencement of infection, while IgG antibodies are seen several weeks later.

Lab tests often ordered with a Lyme Disease Antibodies test:

• Babesia Microti Antibodies
• Bartonella Species Antibodies
• Ehrlichia Chaffeensis Antibodies
• Epstein-Barr Virus Antibody Panel

Conditions where a a Lyme Disease Antibodies test is recommended:

• Lyme Disease

How does my health care provider use a Lyme Disease Antibodies test?

Lyme disease tests are performed to see if a person has been infected with the germs Borrelia burgdorferi or Borrelia mayonii and has the symptoms of the disease. Antibodies generated by the immune system in response to infection are detected by the tests.

IgM and IgG antibodies can be detected via laboratory tests.

Antibodies to Borrelia IgM are frequently present in the blood two to three weeks after exposure. IgM concentrations peak about six weeks and then start to drop.

IgG antibodies are not detectable for many weeks after exposure, peak at four to six months, and can last for several years.

To identify these antibodies and confirm a diagnosis of Lyme disease, the CDC recommends using two alternative procedures. The initial test is designed to be extremely sensitive in order to detect as many Lyme disease cases as possible. When a person does not have Lyme disease but does have another condition, such as another tick-borne disease, syphilis, or an autoimmune ailment like lupus, it may be positive. If the initial test yields a positive result, a second test using a different method is done to validate the findings. 

Lyme disease can be difficult to diagnose at times. If a person has removed a tick from his or her skin, has had a known tick bite, and lives in or has visited an area of the country where Lyme disease is common, the timing of the probable infection can be accurately predicted. However, because the tick is about the size of a pinhead, the bite may go unnoticed. Not everyone will get the rash, and the symptoms that do occur may be nonspecific and flu-like in the beginning, with joint pain that progresses to chronic arthritis and/or neurological problems that appear months later.

What do my Lyme Disease antibodies test results mean?

Antibodies are not produced in a healthy adult who has never been infected with Borrelia germs.

If a person exhibits signs and symptoms, as well as positive EIA or IFA and western blot tests, it is likely that they have Lyme disease.

If a person tests positive for IgM antibody but negative for IgG and western blot, they may have had a recent infection or a false-positive test result.

If an IgM result is undetectable but the IgG and Western blot tests are positive, the person examined is likely to have a later stage infection or to have had an infection previously.

If all tests come out negative, the person's symptoms are either caused by something else or the antibody levels are too low to detect at that time; retesting in 2 to 3 weeks may be required to confirm or rule out infection.

If the IgM and western blot are negative but the IgG is positive, the person has either recovered from Lyme disease or the symptoms are due to cross reactive antibodies plus something else.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

Lyme disease is caused by a tick vector carrying borrelia burgdorferi. Immunoblot testing qualitatively examines with high specificity antibodies in a patient's specimen. Immunoblot testing is appropriate for confirming a detected EIA or IFA test result.

Description: A Magnesium test is a blood test that measures magnesium levels in your blood’s red blood cells and is useful in determining the cause of abnormal levels of magnesium, calcium, and or potassium, and is useful in the evaluation of a wide variety of disorders such as diabetes, kidney disease, and malabsorption.

Also Known As: Magnesium RBC Test, Magnesium Red Bood Cell Test, Mg Test, Mag test

Collection Method: Blood Draw

Specimen Type: Red Blood Cells

Test Preparation: No preparation required

Average Processing Time: 4 to 5 days

When is a Magnesium RBC test ordered?

Magnesium tests may be requested by health professionals as a follow-up to chronically low calcium and potassium levels in the blood. It may also be prescribed if a person exhibits symptoms of a magnesium deficiency, such as twitching, muscle weakness, cramping, disorientation, seizures, or cardiac arrhythmias.

As part of an evaluation of malabsorption, malnutrition, diarrhea, or alcoholism, a health practitioner may prescribe a magnesium level to check for a deficit. Testing may also be done if someone is taking drugs that cause the kidneys to excrete magnesium. When magnesium and/or calcium supplementation is required, the level of magnesium in the blood can be measured at regular intervals to ensure that the medication is working.

A magnesium test, along with kidney function tests such as a BUN and creatinine, may be given on a regular basis when someone has a kidney problem or uncontrolled diabetes to help monitor renal function and ensure that the person is not excreting or retaining excessive quantities of magnesium.

What does a Magnesium RBC test check for?

The magnesium test measures the amount of magnesium in your blood’s serum. Magnesium is a mineral that supports healthy bones, muscle contraction, neuron function, and energy production. It enters the body through the diet and is then absorbed by the small intestine and colon. Bones, cells, and tissues all contain the element magnesium. It is challenging to determine the total magnesium content from blood tests alone since only 1% of the magnesium present in the body is accessible in the blood. However, this test is still useful for figuring out a person's magnesium levels.

Small levels of magnesium can be found in a range of meals, including green vegetables like spinach, whole grains, and nuts. Magnesium is commonly found in foods that contain dietary fiber. The body regulates how much magnesium it receives and excretes or conserves in the kidneys to keep its magnesium level stable.

Magnesium deficiency can occur as a result of malnutrition, malabsorption-related disorders, or excessive magnesium loss via the kidneys. Magnesium overload can occur as a result of taking magnesium-containing antacids or a decrease in the kidneys' ability to eliminate magnesium.

There may be no or few nonspecific symptoms in someone with mild to severe magnesium insufficiency. Nausea, loss of appetite, exhaustion, confusion, muscle cramps, seizures, changes in heart rate, and numbness or tingling are all symptoms of persistent or severe deficits. They can also wreak havoc on calcium metabolism and worsen calcium deficiency. Nausea, muscle weakness, loss of appetite, and an erratic heart rate are some of the symptoms of excess magnesium, which are similar to those of deficiency.

Lab tests often ordered with a Magnesium RBC test:

• Complete Blood Count
• Calcium
• Iron Total and Total Iron binding capacity
• Potassium
• Comprehensive Metabolic Panel
• Lipid Panel
• Phosphorus
• Parathyroid Hormone
• Vitamin D
• Glucose

Conditions where a Magnesium RBC test is recommended:

• Kidney Disease
• Hypothyroidism
• Diabetes
• Alcoholism
• Malnutrition
• Malabsorption
• Diarrhea
• Dehydration
• Parathyroid Diseases
• Addison Disease
• Adrenal Insufficiency

How does my health care provider use a Magnesium RBC test?

Magnesium levels in the blood are measured with a magnesium test. Atypical magnesium levels are most frequently found in conditions or illnesses that result in insufficient or excessive renal excretion of magnesium or impaired intestinal absorption of magnesium. Magnesium levels can be measured to determine the severity of kidney issues, uncontrolled diabetes, and/or uncontrolled diabetes as well as to diagnose gastrointestinal diseases.

Because a low magnesium blood level can lead to chronically low calcium and potassium levels over time, it may be tested to help diagnose calcium, phosphorus, potassium, and/or parathyroid hormone – another component of calcium regulation – problems.

Magnesium levels can be checked on a regular basis to monitor the response to oral or intravenous magnesium supplements, and calcium supplementation can be monitored using calcium and phosphorus tests.

What does my Magnesium RBC test result mean?

Low magnesium levels in the blood can suggest that a person isn't getting enough magnesium or is excreting too much. Deficiencies are most commonly encountered in:

• Low nutritional intake 
• Gastrointestinal conditions
• Diabetes that is uncontrolled
• Hypoparathyroidism
• Use of a diuretic for a long time
• diarrhea that lasts for a long time
• Following surgery
• Burns that are severe
• Pregnancy toxicity

Magnesium levels in the blood are rarely elevated as a result of food sources, but rather as a result of an excretion problem or excessive supplementation. Increased levels can be cause by:

• Failure of the kidneys
• Hyperparathyroidism
• Hypothyroidism
• Dehydration
• Diabetic acidosis
• Addison's disese
• Use of antacids or laxatives containing magnesium

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.