Testing EPO blood levels is thus of value if:
- Too little EPO might be responsible for too few red blood cells (such as in evaluating anemia).
- Too much EPO might be causing too many red blood cells (polycythemia).
- Too much EPO might be evidence for a kidney tumor.
- Too much EPO in an athlete suggests EPO abuse.
The patient is usually asked to fast for 8-10 hours (overnight) and sometimes to lie quietly and relax for 20 or 30 minutes before the test. The test requires a routine sample of blood.
Normal levels of EPO are 0 to 19 (some say up to 24) mU/ml (milliunits per milliliter). Subnormal values of EPO are found for example in anemia due to chronic kidney failure. Elevated EPO levels are found for example in polycythemia rubra vera, a disorder characterized by an excess of red blood cells. The correct interpretation of an abnormal EPO level depends on the patient's particular picture.