Sickle cell anemia is a genetic disorder disease which affects the hemoglobin. It is a condition in which there aren't enough healthy red blood cells to carry adequate oxygen throughout your body. It is a genetically inherited disease, due to which the red blood cells which are usually flexible and round become rigid and sticky, and are shaped like sickles or crescent moons. These irregularly shaped cells can get stuck in small blood vessels, which can slow or block blood flow and oxygen to parts of the body.