Hemolysis is the destruction of red blood cells. Hemolysis can occur due to different causes and leads to the release of hemoglobin into the bloodstream. Normal red blood cells (erythrocytes) have a lifespan of about 120 days. After they die they break down and are removed from the circulation by the spleen. In some medical conditions, or as a result of taking certain medications, this breakdown of red blood cells is increased. Red cells may break down due to mechanical damage, such as from artificial heart valves or heart-lung bypass; or they may be destroyed due to defects in the cells themselves. Medications that have been associated with hemolysis include acetaminophen, penicillin, and other pain medications. Hemolytic anemia is the term used to refer to anemia caused by the excess destruction of red blood cells.