Blood Coagulation

The blood coagulation tests measure your coagulation profile, including INR, APTT, platelets, and fibrinogen. It is a screening test for abnormal blood clotting that examines the factors most often associated with a bleeding problem. Order from Ulta Lab Tests today with confidential results available online in 24 to 48 hours.

Did you know that as many as 900,000 people suffer blood clots each year? Learn why blood coagulation tests are so important for overall health.   

Below the list of tests is a guide that explains and answers your questions on what you need to know about blood coagulation tests, along with information on blood coagulation disorders, signs, symptoms, and diagnosis.


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C4B is a complement binding protein that specifically binds 50% circulating protein S, a vitamin K dependent cofactor of protein C activation. Since C4B may be elevated in certain disease states, this may affect the available "free protein S" to engage in anticoagulant activity.

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Serum calcium is involved in the regulation of neuromuscular and enzyme activity, bone metabolism and blood coagulation. Calcium blood levels are controlled by a complex interaction of parathyroid hormone, vitamin D, calcitonin and adrenal cortical steroids. Calcium measurements are useful in the diagnosis of parathyroid disease, some bone disorders and chronic renal disease. A low level of calcium may result in tetany.

Screening test to aid in diagnosis of disseminated intravascular coagulation (DIC) and acute occlusive vascular disease.

Lupus anticoagulants (LA) are members of a family of antibodies with phospholipid specificity. LA may be defined as an immunoglobulin, IgG or IgM or a mixture of both, that interferes with one or more of the in vitro phospholipid (PL) dependent tests of coagulation. These antibodies are not associated with a hemorrhagic diathesis, but rather have been linked to thrombotic events. In addition to thrombosis other clinical complications have been associated with the presence of LA. These include strokes, nonbacterial thrombotic endocarditis, livedo reticularis and a variety of obstetrical complications such as intrauterine fetal death, recurrent spontaneous abortion, fetal growth retardation, early onset preeclampsia and chorea gravidarum.

Screening test for deficiencies of plasma coagulation factors other than Factors VII and XIII. The test is also used to monitor patients on heparin therapy.

False elevations of potassium may be due to hemolysis or rupture of platelets during coagulation process. The use of plasma potassium levels should be limited to those patients with spuriously elevated or depressed potassium levels due to blood samples left at room temperature, in patients with chronic lymphocytic leukemia with very high WBC counts (false decline), and those with thrombocytosis (increased platelets) with counts in excess of one million (false elevation).

Aids in diagnosis of decreased activity of Protein C characterized by recurrent venous thrombosis. Acquired deficiencies associated with Protein C include: oral anticoagulant therapy, liver disease, vitamin K deficiency, malignancy, consumptive DIC, surgery, trauma, antibodies to Protein C and hepatic immaturity of the newborn.

Comprehensive test assesses the total level of protein and its functional activity in determining Protein C deficiency, which is strongly prothrombotic, and may require long-term anticoagulation therapy. In the presence of low Protein C Activity, Protein C Antigen helps to confirm and to classify Protein C Deficiency as Type I or Type II. Protein C is a highly thrombophilic protein.

In the presence of low Protein C Activity, Protein C Antigen is useful in classifying the deficiency as Type I or II.

Aids in diagnosis of congenital deficiencies characterized by recurrent venous thrombosis. Acquired deficiencies associated with Protein C include: oral anticoagulant therapy, liver disease, vitamin K deficiency, malignancy, consumptive DIC, surgery, trauma, antibodies to Protein C and hepatic immaturity of the newborn.


Screening test for abnormalities of coagulation factors that are involved in the extrinsic pathway. Also used to monitor effects of Warfarin therapy and to study patients with hereditary and acquired clotting disorders.

PT-Screening test for deficiencies of plasma coagulation factors other than Factors VII and XIII. The test is also used to monitor patients on heparin therapy. PTT-Screening test for abnormalities of coagulation factors that are involved in the extrinsic pathway. Also used to monitor effects of Warfarin therapy and to study patients with hereditary and acquired clotting disorders.

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Vitamin K is a required co-factor for the synthesis of factors 2, 7, 9, and 10 and proteins C and S. Deficiencies of vitamin K lead to bleeding. Coumadin® (warfarin) acts as an anticoagulant because it is a vitamin K antagonist


In the United States, 100,000 people die due to blood clots annually. In addition to that, 900,000 people end up dealing with venous thromboembolism every year. These numbers are so high because these blood clots are not caught in time to get taken care of before it becomes a serious problem.

Continue reading to learn more about clotting disorders and blood coagulation tests. 

What Are Clotting Disorders?

The body has a natural blood clotting process known as hemostasis. The body forces the injured blood vessel to constrict, then platelets are sent to the injury site. They attach to the wound and coagulation occurs. 

In clotting disorders, excessive clotting takes place. This is also known as a hypercoagulable state. This allows large blood clots to form where they shouldn't: in the bloodstream. These blood clots make their way to the legs (venous thromboembolism), the lungs (pulmonary embolism), and even the arteries of the heart (arterial thrombosis), and they block off blood vessels.

Clotting Disorders Causes

In some cases, it is acquired via underlying health conditions. These conditions might include:

  • Prolonged immobilization or bed rest
  • Auto-immune disorders (like Lupus)
  • Cancer or malignant tumor growth
  • Catheter use
  • Pregnancy or childbirth
  • Medical drug use (Hormone Replacement Therapy, oral contraceptives, or Heparin)
  • Cholesterol or calcium buildup in the bloodstream
  • Blood vessel inflammation
  • Heart failure
  • Obesity

It can also be an inherited health condition through genetic mutations, such as:

  • Factor V Leiden mutation
  • Prothrombin 20210 mutation
  • MTHFR mutation

It can be an inherited health condition due to:

  • Antithrombin
  • Protein C and S
  • Elevated Factor VII levels

Catching these blood clots early makes all of the difference between life or death in these patients. Knowing the signs can help in diagnosing these blood clots in time to seek treatment. 

Signs and Symptoms of Clotting Disorders

The different signs and symptoms of blood clotting disorders depend on the location of the blood clot. If the clot is in the leg, the symptoms include:

  • Leg pain or tenderness
  • Edema or swelling
  • Discoloration in the leg

If the clot is in the lung, the symptoms might include:

  • Sudden shortness of breath
  • Chest pain
  • Coughing up blood
  • Irregular heartbeat 
  • Fainting or lightheadedness
  • Anxiety

In other areas of the body, blood clot symptoms may mimic a heart attack or a stroke. If you find that you have any of these symptoms, you should speak with your doctor as soon as possible. 

There are certain tests that you can do to check for clotting disorders, so it's a good idea to be proactive if you notice you may have any of the risk factors associated with blood clotting disorders or you have any of the symptoms. 

Clotting Disorder FAQs

Should those with clotting disorders see a specialist? Your primary care physician can care for clotting disorders. However, when you have an active blood clot, you should make sure to see your hematologist to get it taken care of. 

If you are diagnosed with a clotting disorder, should your family members also get tested? Some of these conditions can be genetic. It is always a good idea for your family members to be tested for this disorder.

Who can have a blood clotting disorder? Men and women alike can have a clotting disorder. People of any age can develop a clotting disorder. They are more commonly diagnosed, however, among older teens and adults as they go through the normal changes in their blood.

Why Order Blood Coagulation Tests?

Blood coagulation tests are essential in finding possible blood clots throughout your body as a result of a clotting disorder. The tests that check for blood clotting include:

  • Prothrombin Time (PT)
  • Activated Partial Thromboplastin Time (aPTT)

The Prothrombin Time (PT) test monitors how fast the blood clots. The Activated Partial Thromboplastin Time (aPTT) test monitors how long it takes for the blood to clot.

At Ulta Lab Tests, we also offer a:

  • Complete Blood Count test
  • Fibrinogen level test

The Complete Blood Count test will look for signs of anemia or a low platelet count which can cause abnormal blood clotting. The Fibrinogen test monitors your fibrinogen level (a protein found in the liver). It looks for abnormalities that point to excessive bleeding problems. 

These tests are all performed by a phlebotomist: they are not at-home test kits! We offer these tests at affordable pricing and you don't need a referral or insurance to get this testing done. These tests also come with a 100% satisfaction guarantee. 

Get Started Today!

If you are showing signs of a blood clot, it's important to talk to a health professional immediately. If you are worried that you might have a blood clotting disorder, there are blood clotting tests available for purchase through our website. Once you have the results, you can go over them with your doctor and go from there.

Order your blood coagulation tests today and you will get your results in 24 to 48 hours. Results are then sent by a secure and confidential online server. 

Platelets are also known as thrombocytes. They are found in the bone marrow. They are small fragments or large cells known as megakaryocytes. Platelets are usually released into the blood for circulation and are used in the clotting process.

How Do Platelets Work?

If there is an injury to a blood vessel or a tissue, your body will start bleeding. Platelets will help stop the bleeding in the following ways:

  1. Adhere to the affected area.
  2. Aggregate or clump together with other platelets to create a temporary plug.
  3. Send chemical signals to allow further aggregation of the other platelets.
  4. They also support the coagulation cascade. It’s a process where the clotting factors in the blood are activated to create a blood clot.
  5. Eventually, platelets become a stable blood clot on the injured area. The clot remains in place until the injury is completely healed.

Each microliter of blood contains about 150,000 to 450,000 platelets. A healthy person should have millions of platelets in every single drop of blood. Your body has regular small injuries, so the platelets are repeatedly used up. They can exist for about 8 to 10 days. The bone marrow should produce new platelets to replace the ones that are degraded, lost, or used up through bleeding.

How to Determine the Number of Platelets in Your Body

You can determine the number of platelets in your blood using a platelet count. It is a common test performed as part of a complete blood count (CBC). A CBC can be done as part of your routine health check or when your doctor is examining you for any condition.

The medical professional interprets the platelet count within the context of the other tests performed, such as a CBC, among other factors, including your medical history. If your platelet count is very low, it means your blood has very few platelets.

It means that in the event of an injury, your blood will not clot appropriately, and you are at an increased risk of bruising and excessive bleeding. Keep in mind that a single low platelet count might not necessarily have a huge medical significance. For instance, if the count is slightly lower than the normal range, there is nothing to worry about.

The medical professional should repeat the test and check the previous platelet counts to confirm the same. Any result outside the normal range could indicate a huge problem and prompt further investigation. However, the medical professional should be able to ascertain whether a result outside the normal range is significant in your case.

A low platelet count is also referred to as thrombocytopenia. Various conditions can cause it. It might be acute, where it develops suddenly, temporary or chronic where it persists over time. The risk of serious bleeding because of low platelet count doesn’t happen until you have a very low platelet count (about 20,000 per microliter or even lower).

With a platelet count of about 50,000 per microliter, minor bleeding is present, especially if you have another condition such as kidney disease. The platelet count will drop dramatically depending on the illness, causing the low count.

If you have a severely low platelet count, you are at a high risk of serious bleeding. You should get the necessary treatment to reduce the risk. Several tests will also be performed to determine the exact cause of the low platelet count.

What Are the Causes of a Low Platelet Count?

A few conditions are known to cause a low platelet count. They can be genetic or acquired conditions. If you have an enlarged spleen (happens because of numerous conditions), it will trap platelets, causing a low count.

A low platelet count can be accounted for because of the following:

  • Decreased Production of Platelets

A low platelet count is caused by an interruption of the production of platelets in the bone marrow. Some of the main causes include:

  • Cancer – Some types of cancer such as lymphoma, leukemia, or anything that spreads to the bone marrow will cause a low platelet count. The cancer cells overwhelm the normal bone marrow cells, including the megakaryocytes that form platelets. If you have leukemia, you will have excessive bleeding because of the reduced platelets in the bone marrow.
  • Aplastic Anemia – Here, the bone marrow is failing, so the production of all types of blood cells is reduced significantly.
  • Chemotherapy or Radiation Therapy – If you undergo any of these treatments, the bone marrow’s ability to produce platelets is severely affected.
  • Myelodysplastic Syndrome – It refers to a group of disorders that make the bone marrow ineffective and dysfunctional. As a result, there is reduced production of blood cells, including platelets.
  • Vitamin B12 Or Folate Deficiency – With time, a Vitamin B12 (folate deficiency) can lead to few enlarge red blood cells (a condition known as macrocytic anemia) and fewer platelets.
  • Bone Marrow Infection – Any infections spreading through the blood to the bone or any injury to the bone will result in an infection in the bone marrow. Staphylococcus bacteria mostly cause these infections.
  • Bone Marrow Damage – It is caused by constant exposure to toxic chemicals like benzene or a few types of pesticides.
  • Cirrhosis – It causes reduced production of platelets and a low platelet count.
  • Wiskott-Aldrich Syndrome – It is characterized by a decrease in the size and the total number of platelets in the body. It only affects males.
  • May-Hegglin Anomaly – It results in large misshapen plates reducing the platelets in the body.
  • Gaucher Disease – It is characterized by fatty substances accumulating in the spleen and liver, thus causing them to enlarge and a low platelet count.

Increased Use of Platelets or Destruction

Some conditions lead to platelets being used up and destroyed faster than the bone marrow can produce. It is a huge risk for a low platelet count, but most people with these conditions have a normal count. Some of these conditions include:

  • Viral infections such as hepatitis, mononucleosis, measles, or HIV.
  • Sepsis especially caused by a serious gram-negative bacterial infection such as E. coli or Escherichia.
  • Medication such as quinine, acetaminophen, sulfa antibiotics, vancomycin, digoxin, nitroglycerin, diazepam, gold salts, and diuretics.
  • During pregnancy, platelet count is also known to reduce but remains in the normal range. It is referred to as gestational thrombocytopenia, where the platelet count ranges between 100,000 to 150,000. It happens in at least 10% of women. If the platelet count drops below 100,000, it can be life-threatening and often happens during pre-eclampsia, immune thrombocytopenia, or HELLP syndrome.
  • Dilution – If you receive a massive blood transfusion of red blood cells without getting platelets, you will have a low platelet count.
  • Physical destruction of platelets because of artificial heart valves or medical equipment mostly used during heart bypass surgeries.
  • DIC – It refers to disseminated intravascular coagulation. It is a severe and devastating response that happens because of an infection, burns, or severe trauma. It causes a significant and rapid decrease in the platelets in your body.
  • Hemolytic Uremic Syndrome – It occurs because of a severe toxin that leads to an E. coli infection in the gut, thus destroying red blood cells and platelets.
  • Thrombotic Thrombocytopenic Purpura – It is an acute and life-threatening condition though it’s rare. It leads to clotting and the destruction of red blood cells. Here, tiny clots will form and deposit in various small blood vessels in the body. It leads to the accelerated use of platelets, thus reducing the count. It might be an acquired or genetic condition.
  • Immune-related Conditions – There are some immune-related conditions known to increase the destruction of platelets. The immune system is the natural defense system in the body and protects it against infections. It can distinguish between self and non-self. If you have an autoimmune condition, the body identifies its own proteins as non-self and produces antibodies to target them. The antibodies might target platelets, thus reducing the numbers considerably.

Some of these immune-related conditions include the following:

  • Immune Thrombocytopenia – It is also referred to as immune thrombocytopenic purpura. It affects children. The condition develops after a viral infection and resolves itself after a few months without any treatment. It can affect both boys and girls. In adults, the condition is chronic and affects more women than men.
  • A low platelet count can also be an immune response when you have an autoimmune condition such as rheumatoid arthritis or lupus.
  • Heparin-induced Thrombocytopenia – You will have a low platelet count if you have been on heparin therapy, and your body has a platelet antibody. The condition is characterized by abnormal clotting instead of excessive bleeding.
  • Fetal or Neonatal Alloimmune Thrombocytopenia – It is a rare immune condition and causes a low platelet count in newborn children. It causes when the mother produces antibodies against the developing platelets in the newborn and identifies them as non-self. The antibodies attack and destroy the platelets in the fetus. Most cases of this condition are mild, but serious cases can lead to bleeding and often need treatment.

The Signs And Symptoms To Watch Out For

Depending on your low platelet count, you might not show any signs and symptoms. They are often found during a routine health exam. If the platelet count is considerably low, you might show some of the following signs and symptoms.

  • Unexplained and easy bruising
  • Small red spots on your skin that look like rashes (petechiae)
  • Small purple spots caused by bleeding under your skin (purpura)
  • Excessive bleeding from a wound or a small cut
  • Frequent nosebleeds
  • Bleeding in the digestive tract with black stool
  • Heavy menstrual bleeding
  • Oral bleeding from the gums
  • Intracranial bleeding (inside the head

Tests Needed to Confirm Low Platelet Counts

A low platelet count can be diagnosed, evaluated, and monitored through various blood tests. None of these tests can identify the cause of the low platelet count, but they can be used to identify the right treatment. These include the following:

  • Complete Blood Count – It is used to check the current platelet count and to identify if the bleeding has caused anemia (low hemoglobin levels).
  • Platelet Count – Checks the number of platelets in the blood, and it is part of the CBC test.
  • Blood Smear – It is done using a microscope to check the blood cells, including platelets.
  • Prothrombin Time and Partial Thromboplastin Time – It is used to check the clotting factors for proper clotting.
  • Basic Metabolic Panel or Comprehensive Metabolic Panel – Checks the overall health of your kidneys, liver, and other organs in your body.
  • Bone Marrow Aspiration and Biopsy – Checks cell production in the bone marrow if you have a low platelet count.
  • Heparin-induced Thrombocytopenia – Checks the antibodies against heparin and diagnoses thrombocytopenia. You can get this test if you have undergone or are currently undergoing heparin therapy.
  • Antiphospholipid Antibodies – Used to diagnose an existing autoimmune disease such as antiphospholipid syndrome as the cause of the low platelet count or its association with your platelets.
  • Antinuclear Antibody (ANA) – Used to diagnose an underlying autoimmune disease such as lupus and its association or cause of low platelets.
  • Vitamin B12 And Folate – Any deficiencies in these vitamins cause a low platelet count, anemia, and a low white blood cell count (known as leukopenia).
  • Hepatitis B, C, and HIV – These are viral infections often associated with low platelets. If you have a low platelet count and test positive for these infections, they are the cause of the low platelet count.