Complete Blood Count (CBC) with Differential and Platelets Blood Test Most Popular

The Complete Blood Count (CBC) with Differential and Platelets Blood Test test contains 1 test with 33 biomarkers .

Brief Description: The Complete Blood Count (CBC) with Differential and Platelets test is a comprehensive blood test that evaluates the overall health and function of the blood by measuring red blood cells, white blood cells, hemoglobin, hematocrit, platelets, and the different types of white blood cells (neutrophils, lymphocytes, monocytes, eosinophils, and basophils). It helps detect a wide range of conditions, including infections, anemia, inflammation, immune system disorders, and blood cancers. This test provides valuable insights into the body’s ability to carry oxygen, fight infection, and control bleeding.

Also Known As: CBC Test, Total Blood Count Test, Hemogram test

Testing Method: Electronic Cell Sizing, Counting, Cytometry, and Microscopy

Collection Method: Blood Draw 
Specimen: 4 mL Whole Blood 

Test Preparation: No preparation required 

When is a Complete Blood Count test ordered?  

A CBC test may be ordered in various situations. These include:

1. Routine Check-ups: Doctors often include a CBC test as part of routine check-ups to assess overall health and screen for any underlying blood-related conditions.

2. Evaluation of Symptoms: When a patient presents unexplained symptoms such as fatigue, weakness, frequent infections, bruising, or excessive bleeding, a CBC test can help identify potential causes or abnormalities.

3. Monitoring Chronic Conditions: Patients with chronic conditions like anemia, infections, autoimmune disorders, or blood-related diseases require regular CBC tests to monitor their condition, track treatment effectiveness, and adjust therapies accordingly.

4. Pre-Surgical Assessment: Prior to surgery or invasive medical procedures, doctors order CBC tests to evaluate a patient's blood cell counts and ensure their ability to handle the procedure safely.

What does a Complete Blood Count test check for? 

The complete blood count (CBC) is a blood test that determines the number of cells in circulation. White blood cells (WBCs), red blood cells (RBCs), and platelets (PLTs) are three types of cells suspended in a fluid called plasma. They are largely created and matured in the bone marrow and are released into the bloodstream when needed under normal circumstances. 

A CBC is mainly performed with an automated machine that measures a variety of factors, including the number of cells present in a person's blood sample. The findings of a CBC can reveal not only the quantity of different cell types but also the physical properties of some of the cells. 

Significant differences in one or more blood cell populations may suggest the presence of one or more diseases. Other tests are frequently performed to assist in determining the reason for aberrant results. This frequently necessitates visual confirmation via a microscope examination of a blood smear. A skilled laboratory technician can assess the appearance and physical features of blood cells, such as size, shape, and color, and note any anomalies. Any extra information is taken note of and communicated to the healthcare provider. This information provides the health care provider with further information about the cause of abnormal CBC results. 

The CBC focuses on three different types of cells: 

WBCs (White Blood Cells) 

The body uses five different types of WBCs, also known as leukocytes, to keep itself healthy and battle infections and other types of harm. The five different leukocytes are eosinophiles, lymphocytes, neutrophiles, basophils, and monocytes. They are found in relatively steady numbers in the blood. Depending on what is going on in the body, these values may momentarily rise or fall. An infection, for example, can cause the body to manufacture more neutrophils in order to combat bacterial infection. The amount of eosinophils in the body may increase as a result of allergies. A viral infection may cause an increase in lymphocyte production. Abnormal (immature or mature) white cells multiply fast in certain illness situations, such as leukemia, raising the WBC count. 

RBCs (Red Blood Cells) 

The bone marrow produces red blood cells, also known as erythrocytes, which are transferred into the bloodstream after maturing. Hemoglobin, a protein that distributes oxygen throughout the body, is found in these cells. Because RBCs have a 120-day lifespan, the bone marrow must constantly manufacture new RBCs to replace those that have aged and disintegrated or have been lost due to hemorrhage. A variety of diseases, including those that cause severe bleeding, can alter the creation of new RBCs and their longevity. 

The CBC measures the number of RBCs and hemoglobin in the blood, as well as the proportion of RBCs in the blood (hematocrit), and if the RBC population appears to be normal. RBCs are generally homogeneous in size and shape, with only minor differences; however, considerable variances can arise in illnesses including vitamin B12 and folate inadequacy, iron deficiency, and a range of other ailments. Anemia occurs when the concentration of red blood cells and/or the amount of hemoglobin in the blood falls below normal, resulting in symptoms such as weariness and weakness. In a far smaller percentage of cases, there may be an excess of RBCs in the blood (erythrocytosis or polycythemia). This might obstruct the flow of blood through the tiny veins and arteries in extreme circumstances. 

Platelets 

Platelets, also known as thrombocytes, are small cell fragments that aid in the regular clotting of blood. A person with insufficient platelets is more likely to experience excessive bleeding and bruises. Excess platelets can induce excessive clotting or excessive bleeding if the platelets are not operating properly. The platelet count and size are determined by the CBC. 

Understanding Your CBC (Complete Blood Count) With Differential & Platelets

(Quest Diagnostics test #6399)

We know lab reports can feel confusing—especially when money, health worries, and missing numbers are involved. The guide below explains what you’ll always see on a CBC and why a few items sometimes don’t show up. Our goal is to give you clear answers and a little peace of mind.

What you will always get back

These numbers always print unless the sample is damaged.

What only appears if the machine or technologist finds it

Why a line might be missing

1. Nothing to report: If the analyzer sees zero immature cells, it leaves that line off.

2. Everything looked normal: When the automated system is happy with the results, a human slide review isn’t triggered—so no extra notes appear.

3. Can’t measure: Sometimes cells clump, so a value (like MPV) can’t be calculated. In that case the line disappears or shows “unable to report.”

What this means for you

• Fewer lines are usually good news. It often means your blood looks normal.

• Extra lines aren’t automatically bad, but they give your doctor more clues about infection, inflammation, or bone-marrow stress.

• Still worried or confused? Share the report with your healthcare provider or contact us directly. We’re here to help you understand every number you paid for—and to make things right if something was truly missed.

Bottom line: the core numbers you need for a general health check are always there, and the lab automatically adds extra details only when they matter.

Lab tests often ordered with a Complete Blood Count test: 

1. Basic Metabolic Panel (BMP) or Comprehensive Metabolic Panel (CMP):

   • Purpose: These panels measure glucose, calcium, and electrolytes (sodium, potassium, carbon dioxide, chloride), and kidney function (blood urea nitrogen (BUN) and creatinine). The CMP includes additional tests for liver function (ALP, ALT, AST, bilirubin).
   • Why is it ordered with a CBC: These panels provide a general overview of a person's metabolism and organ function and can help determine the cause of symptoms like fatigue or weakness that might be related to abnormalities found on a CBC.

2. Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (CRP):

   • Purpose: These are markers of inflammation in the body. They are not specific but can indicate the presence of an inflammatory process.
   • Why is it ordered with a CBC: If a CBC shows abnormalities such as an elevated white blood cell count, these tests can help determine if inflammation or infection is present.

3. Coagulation tests (Prothrombin Time (PT), International Normalized Ratio (INR), Activated Partial Thromboplastin Time (aPTT)):

   • Purpose: These tests assess blood clotting function and are important if the platelet count or function is abnormal, or if there is a concern about bleeding or clotting disorders.
   • Why is it ordered with a CBC: Abnormal platelet counts from a CBC could signal a bleeding or clotting disorder that would warrant these tests.

4. Iron studies:

   • Purpose: These tests measure different aspects of the body's iron storage and transport and can help diagnose iron-deficiency anemia or hemochromatosis (iron overload).
   • Why is it ordered with a CBC: If the CBC indicates anemia, particularly microcytic anemia (small red blood cells), iron studies can help determine if iron deficiency is the cause.

5. Vitamin B12 and Folate levels:

   • Purpose: These vitamins are crucial for the production of red blood cells, and their deficiency can cause macrocytic anemia (large red blood cells).
   • Why is it ordered with a CBC: If the CBC shows macrocytosis, measuring B12 and folate levels can help find the underlying issue.

6. Lactate Dehydrogenase (LDH):

   • Purpose: LDH is an enzyme found throughout the body, and high levels can indicate cell damage.
   • Why is it ordered with a CBC: Elevated LDH may accompany certain types of hemolytic anemia or other conditions that cause a high turnover of cells, which could be suggested by a CBC.

7. Reticulocyte Count:

   • Purpose: This test measures the number of young red blood cells in the blood, providing information about bone marrow function.
   • Why is it ordered with a CBC: A reticulocyte count can help determine if the bone marrow is responding appropriately to anemia by producing new red blood cells.

The specific tests ordered alongside a CBC with differential and platelets will depend on the clinical scenario, the initial CBC results, and the suspected or differential diagnoses that the healthcare provider is considering.

Conditions where a Complete Blood Count test is recommended: 

A CBC test can assist in diagnosing and monitoring various conditions or diseases, including:

1. Anemia: CBC helps identify different types of anemia, such as iron deficiency anemia, vitamin B12 deficiency anemia, or autoimmune hemolytic anemia.

2. Infections: An abnormal CBC count can indicate the presence of an infection, whether bacterial, viral, or fungal. It provides information about the severity and type of infection.

3. Leukemia: CBC abnormalities may suggest the presence of certain blood cancers, including leukemia. Further tests are necessary to confirm the diagnosis.

4. Inflammatory Disorders: Conditions like rheumatoid arthritis, lupus, or vasculitis can cause changes in the CBC results, indicating ongoing inflammation or autoimmune processes.

How does my healthcare provider use a Complete Blood Count test? 

Health care providers use the results of a CBC test to:

1. Confirm Diagnoses: Abnormal CBC findings help in diagnosing specific conditions or diseases, such as anemia, infections, blood disorders, or certain cancers.

2. Monitor Treatment Progress: Regular CBC tests allow doctors to evaluate the effectiveness of treatments or therapies and make necessary adjustments based on blood cell count improvements or changes.

3. Guide Further Investigations: If CBC results indicate abnormalities, doctors may recommend additional specialized tests or refer the patient to a hematologist or other relevant specialists for further evaluation and diagnosis.

By understanding the purpose, significance, and applications of a CBC test, patients and healthcare providers can utilize this valuable diagnostic tool to aid in the management of various health conditions and ensure optimal patient care.

What do my Complete Blood Count results mean? 

A low Red Blood Cell Count, also known as anemia, could be due many different causes such as chronic bleeding, a bone marrow disorder, and nutritional deficiency just to name a few. A high Red Blood Cell Count, also known as polycythemia, could be due to several conditions including lung disease, dehydration, and smoking. Both Hemoglobin and Hematocrit tend to reflect Red Blood Cell Count results, so if your Red Blood Cell Count is low, your Hematocrit and Hemoglobin will likely also be low. Results should be discussed with your health care provider who can provide interpretation of your results and determine the appropriate next steps or lab tests to further investigate your health. 

What do my Differential results mean? 

A low White Blood Cell count or low WBC count, also known as leukopenia, could be due to a number of different disorders, including autoimmune issues, severe infection, and lymphoma. A high White Blood Cell count, or high WBC count, also known as leukocytosis, can also be due to many different disorders, including infection, leukemia, and inflammation. Abnormal levels in your White Blood Cell Count will be reflected in one or more of your different white blood cells. Knowing which white blood cell types are affected will help your healthcare provider narrow down the issue. Results should be discussed with your healthcare provider, who can provide an interpretation of your results and determine the appropriate next steps or lab tests to further investigate your health. 

What do my Platelet results mean? 

A low Platelet Count, also known as thrombocytopenia, could be due to a number of different disorders, including autoimmune issues, viral infection, and leukemia. A high Platelet Count, also known as Thrombocytosis, can also be due to many different disorders, including cancer, iron deficiency, and rheumatoid arthritis. Results should be discussed with your healthcare provider, who can provide an interpretation of your results and determine the appropriate next steps or lab tests to further investigate your health. 

Anemia and Related Conditions: Key Test Patterns

This table simplifies the interpretation of key test results in anemia and related conditions testing.

Most Common Questions about the Complete Blood Count with Differential and Platelets test:

Test Purpose and Frequency

What is the purpose of a Complete Blood Count with Differential and Platelets test?

This test provides detailed information about the types and numbers of cells in the blood: red blood cells, white blood cells, and platelets. It's often used as a broad screening test to evaluate your general health status, and can also be used to diagnose and monitor a variety of diseases and conditions.

How frequently should I get a CBC with Differential and Platelets test?

The frequency of this test varies depending on various factors like your age, health history, and any ongoing treatments. If you're in good health, your doctor might recommend it as part of a routine physical examination. For those with a chronic condition, such as heart disease or kidney disease, your doctor may recommend frequent CBC tests to monitor your condition.

Components and Normal Ranges

What does a CBC with Differential and Platelets test measure?

This test measures several components: Red blood cell (RBC) count, hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red cell distribution width (RDW), platelet count, mean platelet volume (MPV), white blood cell (WBC) count, and the proportions of different types of white blood cells (neutrophils, lymphocytes, monocytes, eosinophils, and basophils).

What is the normal range for each component of the Complete Blood Count with Differential and Platelets test?

The normal ranges can vary slightly depending on the patient's gender and age, but in general, they are as follows:

• Red blood cell count: Men, 4.2-5.8 million cells/uL; Women, 3.8-5.1 million cells/uL
• Hemoglobin: Men, 13.2-17.1 g/dL; Women, 11.7-15.5 g/dL
• Hematocrit: Men, 38.5%-50.0%; Women, 35.0%-45.0%
• White blood cell count: 3,800 to 10,800 cells/uL
• Platelet count: 140 to 400 thousand/uL

Understanding Test Results

What does a high white blood cell count mean in a CBC with Differential and Platelets test?

A high white blood cell count could suggest that your body is fighting an infection. It might also indicate an immune system disorder, inflammation, or leukemia. Certain drugs, like corticosteroids, can also cause an elevated white blood cell count.

What does a low white blood cell count mean in a CBC with Differential and Platelets test?

A low white blood cell count could suggest a bone marrow problem or that a disease or condition is damaging your immune system. It might be due to chemotherapy, radiation therapy, certain diseases such as lupus or liver disease, or certain drugs that damage white blood cells.

What does a high red blood cell count mean in a CBC with Differential and Platelets test?

A high red blood cell count could indicate a condition such as polycythemia vera or heart disease. Dehydration, kidney disease, and living at a high altitude can also elevate your red blood cell count.

What does a low red blood cell count mean in a CBC with Differential and Platelets test?

A low red blood cell count indicates anemia, which can be caused by various conditions such as blood loss, iron deficiency, bone marrow problems, or kidney disease.

What does a high platelet count mean in a CBC with Differential and Platelets test?

A high platelet count can occur in response to an infection, inflammation, cancer, or a bone marrow condition. It can also occur after having your spleen removed.

What does a low platelet count mean in a CBC with Differential and Platelets test?

A low platelet count can be due to a variety of causes such as an enlarged spleen, an autoimmune disease, a bone marrow disorder, or certain medications. It may also be a result of heavy alcohol use or vitamin B12 deficiency.

Interpretation of Differential Results

What does the 'differential' part of the Complete Blood Count with Differential and Platelets test refer to?

The 'differential' refers to a detailed breakdown of the different types of white blood cells in your blood. It provides information on the percentage of each type relative to the total white blood cell count.

What can the differential reveal about my health in the CBC with Differential and Platelets test?

Changes in the number or percentage of different types of white blood cells can provide insights into various health conditions. An increase in neutrophils, for example, may indicate an acute infection, while an increase in lymphocytes may be seen in chronic infections or certain types of cancers.

Health Conditions and CBC

Can the CBC with Differential and Platelets test detect cancer?

While a CBC with differential cannot diagnose cancer on its own, it can provide clues that something is wrong, prompting further investigation. Certain types of cancers, such as leukemia or multiple myeloma, can cause significant changes in the blood cell counts.

Can a CBC with Differential and Platelets test indicate an infection?

Yes, a CBC with differential can often suggest an infection if there's an elevated white blood cell count, particularly neutrophils. However, the CBC cannot identify the specific type of infection (bacterial, viral, fungal), and further tests may be needed.

Can a CBC with Differential and Platelets test indicate if I have anemia?

Yes, a CBC can indicate anemia. If you have a low red blood cell count, low hemoglobin, or low hematocrit, you may have anemia. The MCV can provide additional information about the cause of the anemia.

Can a CBC with Differential and Platelets test detect autoimmune diseases?

The CBC with differential itself cannot diagnose an autoimmune disease, but it can provide important clues. For instance, certain autoimmune diseases may cause changes in white blood cell counts, such as an increase in the number of lymphocytes or a decrease in the number of neutrophils. Additionally, some autoimmune diseases like lupus or rheumatoid arthritis may lead to anemia, which would be indicated by low red blood cell counts or hemoglobin levels. However, diagnosing an autoimmune disease typically requires a combination of blood tests, including more specific antibody tests, along with clinical symptoms and other diagnostic criteria.

Interpretation of Other CBC Components

What does it mean if my MCV level is high in a CBC with Differential and Platelets test?

MCV stands for mean corpuscular volume and it measures the average size of your red blood cells. A high MCV indicates that your red blood cells are larger than normal, which can be caused by a vitamin B12 or folate deficiency, liver disease, or excessive alcohol use.

What does it mean if my MCV level is low in a CBC with Differential and Platelets test?

A lowMCV indicates that your red blood cells are smaller than normal, a condition called microcytosis. This is often seen in conditions such as iron deficiency anemia or thalassemia.

What does a high RDW in a CBC with Differential and Platelets test mean?

RDW, or red cell distribution width, measures the variation in size and shape of your red blood cells. A high RDW means there is a large variation in size, which can be an early sign of conditions such as iron deficiency anemia, vitamin B12 deficiency, or folate deficiency.

What happens if my hemoglobin is low in a CBC with Differential and Platelets test?

Low hemoglobin levels indicate anemia, which can be caused by a variety of conditions including iron deficiency, vitamin B12 deficiency, blood loss, or a chronic disease. Symptoms can include fatigue, weakness, pale skin, and shortness of breath.

What happens if my hemoglobin is high in a CBC with Differential and Platelets test?

High hemoglobin could suggest polycythemia, a disorder in which your body makes too many red blood cells. This could be a response to chronically low oxygen levels in your blood due to lung disease, living at a high altitude, or it could be caused by a bone marrow disorder.

What does a high MPV mean in a CBC with Differential and Platelets test?

MPV stands for mean platelet volume. A high MPV value could suggest that your body is producing larger platelets, which might happen in certain types of anemia, in response to inflammation, or when your spleen isn’t working properly.

What does a low MPV mean in a CBC with Differential and Platelets test?

A low MPV value might occur when your body is producing smaller than normal platelets, which can be seen in conditions such as aplastic anemia or some inherited disorders.

Can a CBC with Differential and Platelets test indicate if I have a bleeding disorder?

While the CBC test cannot directly diagnose a bleeding disorder, it can provide useful information. For example, if your platelet count is low or if the platelets are not functioning properly, it could indicate a bleeding disorder. Further specific tests would be required to diagnose a bleeding disorder.

Can a CBC with Differential and Platelets test detect blood clotting disorders?

The CBC test is not designed to diagnose clotting disorders. However, it might provide some indications, like a high platelet count, that could suggest a clotting disorder. Additional specialized tests are typically needed to diagnose clotting disorders.

Reflex Information for the Complete Blood Count with Differential and Platelets test

Reflex Parameters for Manual Slide Review

CBC Reflex Pathway

Step 1 - The slide review is performed by qualified Laboratory staff and includes:

• Confirmation of differential percentages
• WBC and platelet estimates, when needed
• Full review of RBC morphology
• Comments for toxic changes, RBC inclusions, abnormal lymphs, and other
• significant findings
• If the differential percentages agree with the automated counts and no abnormal cells are seen, the automated differential is reported with appropriate comments

Step 2 - The slide review is performed by qualified Laboratory staff and includes: If any of the following are seen on the slide review, Laboratory staff will perform a manual differential:

• Immature, abnormal, or toxic cells
• nRBC’s
• Disagreement with automated differential
• Atypical/abnormal RBC morphology
• Any RBC inclusions

Step 3 - If any of the following are seen on the manual differential, a Pathologist will review the slide:

• WBC<1,500 with abnormal cells noted
• Blasts/immature cells, hairy cell lymphs, or megakaryocytes
• New abnormal lymphocytes or monocytes
• Variant or atypical lymphs >15%
• Blood parasites
• RBC morphology with 3+ spherocytes, RBC inclusions, suspect Hgb-C,
• crystals, Pappenheimer bodies or bizarre morphology
• nRBC’s

Sources for Anemia Table

1. Camaschella, C. (2015). Iron-deficiency anemia. New England Journal of Medicine, 372(19), 1832–1843. https://doi.org/10.1056/NEJMra1401038

2. Green, R., & Datta Mitra, A. (2017). Megaloblastic anemias: Nutritional and other causes. Medical Clinics of North America, 101(2), 297–317. https://doi.org/10.1016/j.mcna.2016.09.013

3. Means, R. T., & Glader, B. (2020). Anemia: General considerations. In Wintrobe's Clinical Hematology (14th ed., pp. 587–608). Lippincott Williams & Wilkins.

4. National Institutes of Health (NIH). (2021). Iron: Fact sheet for health professionals. Retrieved from https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/

5. National Institutes of Health (NIH). (2021). Vitamin B12: Fact sheet for health professionals. Retrieved from https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/

6. National Institutes of Health (NIH). (2021). Folate: Fact sheet for health professionals. Retrieved from https://ods.od.nih.gov/factsheets/Folate-HealthProfessional/

7. Weiss, G., & Goodnough, L. T. (2005). Anemia of chronic disease. New England Journal of Medicine, 352(10), 1011–1023. https://doi.org/10.1056/NEJMra041809

8. Tefferi, A. (2003). Anemia in adults: A contemporary approach to diagnosis. Mayo Clinic Proceedings, 78(10), 1274–1280. https://doi.org/10.4065/78.10.1274

Keywords: Complete Blood Count Test, CBC with Differential and Platelets Test