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Definition
By Mayo Clinic staffA complete blood count (CBC) is a blood test used to evaluate your overall health and detect a wide range of disorders, including anemia, infection and leukemia.
A complete blood count test measures several components and features of your blood, including:
- Red blood cells, which carry oxygen
- White blood cells, which fight infection
- Hemoglobin, the oxygen-carrying protein in red blood cells
- Hematocrit, the proportion of red blood cells to the fluid component, or plasma, in your blood
- Platelets, which help with blood clotting
Abnormal increases or decreases in cell counts as revealed in a complete blood count may indicate that you have an underlying medical condition that calls for further evaluation.
Why it's done
References
- Nicoll D, et al. Complete blood cell count. In: Nicoll D, et al. Pocket Guide to Diagnostic Tests. 5th ed. New York, N.Y.: The McGraw-Hill Companies; 2008. http://www.accessmedicine.com/popup.aspx?aID=3135998. Accessed Dec. 9, 2008.
- Patient education: Understanding your complete blood count. National Institutes of Health. http://www.cc.nih.gov/ccc/patient_education/pepubs/cbc97.pdf. Accessed Dec. 9, 2008.
- Complete blood count. Lab Tests Online. http://labtestsonline.org/understanding/analytes/cbc/test.html. Accessed Dec. 9, 2008.
- Fischbach FT. Blood studies: Hematology and coagulation. In: Fischbach FT. A Manual of Laboratory and Diagnostic Tests. 8th ed. Philadelphia, Pa.: Lippincott Williams & Wilkins; 2009:58.
- Tefferi A, et al. How to interpret and pursue an abnormal complete blood cell count in adults. Mayo Clinic Proceedings. 2005;80:923.
- Laboratory reference values. Erythrocytes: Red blood cells, hemoglobin. Leukocytes: White blood cells, platelet count, hematocrit. Rochester, Minn.: Mayo Foundation for Medical Education and Research; Dec. 2008.
