Erythropoietin is a naturally occuring hormone growth factor that stimulates the formation of red blood cells. (EPO) was used to treat anemia resulting from renal failure or cancer chemothreapy. It can be easily injected under the skin, and the use of EPO is now used wide-spread in endurance sports.
Excessive use of the hormone can raise hermatocrit above 70% which can cause polycythemia, a condition where the level of red blood cells in the blood is abnormally high. This causes the blood to be more viscous than normal, a condition that strains the heart. EPO can cause the heart rate to drop abnormally low, especially during sleep where they have high concentrations of red blood cells in their blood. Red blood cell count goes down with age, EPO should not be used to replace them as it has major health benefits. The increasing number of red blood cells in the blood make it thicker, which can also make it clot more readily. This increases the risk of heart attacks, strokes and pulmonary embolism. Blood contamination and disease from injections and blood doping can lead to infection that affects the whole body.
