Why it's doneBy Mayo Clinic staff
A hematocrit test is part of a complete blood count (CBC). The proportion of red blood cells compared with all blood cells may help your doctor make a diagnosis or monitor your response to a treatment.
A lower than normal hematocrit may indicate:
- An insufficient supply of healthy red blood cells (anemia)
- A large number of white blood cells — usually a very small portion of your blood — due to long-term illness, infection, leukemia, lymphoma or other disorders of white blood cells
- Vitamin or mineral deficiencies
- Recent or long-term blood loss
A higher than normal hematocrit may indicate:
- A disorder, such as polycythemia vera, that causes your body to produce too many red blood cells
- Lung or heart disease — if the body senses low oxygen levels, it will make more red blood cells in an effort to increase the amount of oxygen in the blood
- Lichtman MA, et al. Williams Hematology. 8th ed. New York, N.Y.: The McGraw-Hill Companies; 2010.
- http://www.accessmedicine.com/resourceTOC.aspx?resourceID=69. Accessed May 30, 2013.
- Hematocrit. Lab Tests Online. http://labtestsonline.org/understanding/analytes/hematocrit/tab/test. Accessed May 30, 2013.
- CBC with differential, blood. Mayo Medical Laboratories. http://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/9109. Accessed March 25, 2013.
- Schrier SL. Approach to the adult patient with anemia. http://www.uptodate.com/home. Accessed May 30, 2013.