Erythropoietin (Blood)

EPO

This is a test to measure how much erythropoietin (EPO) you have in your blood. EPO is a hormone that your kidney makes to trigger your bone marrow to make red blood cells. A normal EPO level means that your body can make healthy red blood cells.

Healthy oxygen levels are linked to having enough red blood cells. For this reason, EPO levels usually rise when your body isn't getting enough oxygen. 

You may need this test if other tests have shown that you have anemia, and your healthcare provider wants to figure out what kind of anemia you have. They might also order this test to help find out whether your kidneys are making a normal amount of EPO. A level of EPO that’s higher than normal may mean you have a kidney tumor.

If you are a professional cyclist, long-distance runner, or other professional athlete, you may be asked to take this test. It's sometimes used to find out whether athletes have been using EPO to improve their performance. 

Because EPO plays a key role in the making of red blood cells, your healthcare provider may order other blood tests. These include a complete blood count, or CBC. Your provider may also order other tests for anemia. These could include tests for iron levels, total iron binding capacity level, ferritin levels, and reticulocyte counts.

Test results may vary depending on your age, gender, health history, and other things. Your test results may be different depending on the lab used. They may not mean you have a problem. Ask your healthcare provider what your test results mean for you.

The normal range for EPO levels can vary from 4 to 26 milliunits per liter (mU/mL). Higher-than-normal levels may mean you have anemia. In severe cases of anemia, EPO levels in the blood may be a thousand times higher than normal.

Unusually low levels may be because of polycythemia vera. This is a bone marrow disorder that causes your body to make too many red blood cells. Low EPO levels may also mean you have kidney disease. 

The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand. 

Having a blood test with a needle carries some risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Afterward, the site may be sore. 

Ask your healthcare provider about what might affect your results. Donating blood can raise the EPO level in your blood. Pregnancy and certain medicines can also affect this test.

You don't need to prepare for this test. Be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.