Complete Blood Count Test | CBC Blood Test

What

Measures the amount of red blood cells (RBCs), white blood cells (WBCs), and platelets in your blood.

Who

Must be 18+ years of age to purchase.

How

Blood

Where

Find a location near you

Schedule an appointment, then visit a Quest Diagnostics patient service center location.

About the Test

This test with differential measures and evaluates the components of your blood cells, including red blood cells (RBCs), white blood cells (WBCs), and platelets. Red blood cells carry oxygen throughout your body. Abnormal levels can help identify conditions such as anemia, malnutrition, leukemia, and others. White blood cells are an important part of your immune system, and abnormal levels may mean your body is fighting an infection. Platelets help your blood clot normally.

The CBC provides valuable information from measurements of the type, number and size of cells in your blood. Red blood cell measurements include the number of red blood cells, or RBC count, the amounts of hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and red cell distribution width (RDW). Measurements of while blood cells include number of cells or WBC count, as well as measures of the different kinds of white blood cells—this is what “differential” means. The CBC provides information about your neutrophils, lymphocytes, monocytes, eosinophils, and basophils the number, or count, of platelets; and mean platelet volume (MPV).

The CBC measures multiple components of your blood to help identify bleeding disorders or infections and abnormal levels of specific blood components. For instance, a CBC measures the level of red blood cells, which transport oxygen to body cells and tissues. A low level of RBCs can be a sign of anemia. High levels of abnormal white blood cells that crowd out red blood cells and platelets can be a sign of leukemia. This test measures various components and abnormalities of your blood, including: RBC count, hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) and red cell distribution width (RDW), WBC count, WBC Differential (neutrophils, lymphocytes, monocytes, eosinophils, and basophils), platelet count, and mean platelet volume (MPV).

The presence of red blood cells may indicate the presence of a health condition, such as kidney or liver disease, a urinary tract infection, or another urinary disorder.

Hemoglobin is the primary protein found in red blood cells and is responsible for the bright red color of our blood. Hemoglobin attaches to oxygen and carbon dioxide molecules, delivering oxygen from the lungs to tissues throughout the body, and carrying away excess carbon dioxide.

Hematocrit is the portion of your total blood volume taken up by red blood cells. This is different from the red blood cell count. Hematocrit is expressed as a percentage based on the number and size of red blood cells. This value can indicate whether your blood contains an abnormally low, or high, proportion of red blood cells in relation to white blood cells and platelets.

The mean corpuscular volume is a measurement used to describe the average size of red blood cells.

The mean corpuscular hemoglobin value represents the average amount of hemoglobin contained in each red blood cell.

The mean corpuscular hemoglobin concentration measures the average amount of hemoglobin per red blood cell relative to the size of the cell.

The red cell distribution width indicates the range of size variation and similarity of your red blood cells.

A platelet count measures the number of platelets per microliter in your blood sample. Platelets, alternatively referred to as thrombocytes, are small blood cells that assist in stopping bleeding by swelling and clumping together to create a clot. Additionally, platelets store and transport a variety of substances such as serotonin, epinephrine, and histamine.

The mean platelet volume (MPV) measures the average size of platelets in your blood. MPV is associated with exercise performance, but it also plays a role in blood clotting and inflammation.

These are the infection-fighting cells: the presence of white blood cells in the urine indicates a bacterial infection in the urinary tract or kidneys.

Neutrophils, a type of granulocyte, are the most prevalent form of white blood cells, accounting for more than half of the quantity in your body. These cells travel to the site of an infection, where they consume the pathogen and release enzymes to eliminate it. Additionally, neutrophils enhance the response of other immune cells.

There are 2 types of lymphocytes, B cells and T cells. B cells produce antibodies in response to bacteria, viruses, and toxins. T cells destroy the body's own cells that have been infected with viruses or have developed cancer. Both types of cells protect against future invasions of bacteria, viruses, and parasites by generating antibodies.

Monocytes are the largest cells in the blood. They travel through the bloodstream to tissues throughout the body, becoming either a macrophage or dendritic cell. Macrophages ingest harmful microbes, remove dead cells, and trigger an immune response. Dendritic cells are responsible for capturing, transporting, and presenting antigens derived from pathogens to immune cells that can fight them.

Eosinophils, a type of granulocyte, are found in the bloodstream and the lining of various organs. These disease-fighting white blood cells contain proteins to help the body fight bacterial and parasitic infections. However, if eosinophil levels rise too high, they can contribute to allergic reactions and other inflammatory responses in the body.

Basophils, a type of granulocyte, are present in both the blood and tissues, and like other white blood cells, they help protect the body against harmful substances. Importantly, basophils play a role in releasing antibodies that can fight bacteria and parasites like fungi, tick-borne diseases, and worms. These WBCs also contain heparin, which prevents blood from excessive clotting, and histamine, which increases blood flow to tissues. Like eosinophils, if their numbers climb too high, they can contribute to allergies and other inflammatory reactions in the body.

You must be 18 years of age or older to purchase. Purchases not permitted in: AK, AZ, HI.

You do not need to do anything special to prepare for the sample collection. This panel does not require fasting.

When your results are ready, we will send them to you in a clear, easy-to-read report. You will have the option to speak with an independent physician to discuss your results. If your results differ from expected ranges, you may receive an alert call to inform you. Your test results will be available to you a few days after we collect your sample.

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After your purchase, schedule an appointment at a nearby Quest Diagnostics location and have your specimen sample collected by a trained healthcare professional.

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Access test results from your phone as soon as they’re available, with the option to discuss your results with an independent physician at no extra cost.

Your results are available on our free, secure patient portal that you can access on your smartphone, tablet, or desktop. You will receive an email notification when your results are ready. You can also share your results with your healthcare provider, family, or friends.

FAQs

Are there other names for a Complete Blood Count test?

Yes, the Complete Blood Count may also be referred to as CBC, Complete Blood Count with Differential, CBC with Diff, Blood Cell Count, or Full Blood Count.

What is the difference between a complete blood count with differential and a standard CBC?

A standard CBC counts the overall amount of white blood cells without distinguishing between the different types of WBCs. A CBC with differential classifies and measures the individual amounts of the 5 different types of WBCs: neutrophils, lymphocytes, monocytes, eosinophils, and basophils.

Is anemia the same as an iron deficiency?

No, anemia is caused by insufficient levels of hemoglobin, whereas a lack of iron causes iron deficiency.

It's possible to have an iron deficiency while maintaining a normal hemoglobin level despite your body being deficient in iron. However, a person with iron deficiency anemia has neither sufficient levels of hemoglobin nor iron. It's important to note that anemia can also be caused by issues other than iron imbalance, such as blood loss, inflammation, other nutrient deficiencies, and certain health conditions.

Complete Blood Count (CBC)