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CBC - Complete Blood Count

The CBC (complete blood count) is one of the most common types of blood test. It's often done as part of a routine checkup.

A CBC measures many different parts of your blood (as described below). This test can help detect blood diseases and disorders. These include anemia, infection, clotting problems, blood cancers, and immune system disorders.

Result ranges for common blood tests

NOTE: All values in this section are for adults only. They don’t apply to children. Talk to your child’s doctor about values on blood tests for children.

The list below shows some normal ranges for different components of the complete blood count (CBC). Some of the normal ranges are different for men and women. Other factors, such as age and race, also may affect normal ranges.

Your doctor should discuss your results with you. He or she will advise you further if your results are outside the normalrange for your group.

Complete Blood Count (CBC) Blood Test

* Cells/mcL = cells per microliter; gm/dL = grams per deciliter

Red blood cells (RBCs)

Red blood cells carry oxygen from your lungs to the rest of your body. Abnormal red blood cell levels may be a sign of anemia, dehydration (too little fluid in the body), bleeding, or another disorder.

White blood cells (WBCs)

White blood cells are part of your immune system, which fights infections and disease. Abnormal white blood cell levels may be a sign of infection, blood cancer, or an immune system disorder.

A CBC measures the overall number of white blood cells in your blood. A differential count looks at the amounts of different types of white blood cells in your blood.

Platelets

Platelets are blood cells that help your blood clot. They stick together to seal cuts or breaks and stop bleeding. Abnormal platelet levels may be a sign of a bleeding disorder (not enough clotting) or a thrombotic disorder (too much clotting).

Hemoglobin (Hgb)

Hemoglobin is an iron-rich protein in red blood cells that carries oxygen. Abnormal hemoglobin levels may be a sign of anemia, sickle cell anemia, thalassemia, or other blood disorders.

If you have diabetes, excess glucose in your blood can attach to hemoglobin and raise the level of hemoglobin A1c.

Hematocrit (Hct)

Hematocrit is a measure of how much space red blood cells take up in your blood. A high hematocrit level might mean you're dehydrated. A low hematocrit level might mean you have anemia. Abnormal hematocrit levels also may be a sign of a blood or bone marrow disorder.

Mean corpuscular volume

Mean corpuscular volume (MCV) is a measure of the average size of your red blood cells. Abnormal MCV levels may be a sign of anemia or thalassemia.


Reference: The National Heart, Blood, and Lung Institute

Last updated April 27, 2017