The spleen is a small abdominal organ located behind the stomach and below the diaphragm. Although it is known the spleen is responsible for the processing of dead red blood cells, its other purposes and functions are unknown. A person can live without a spleen, but persons without a spleen are more susceptible to septicemia. It is therefore believed the spleen has a role in fighting blood infections. It also stores platelets and releases them in situations where clotting blood is vital, such as a serious injury.
An injury to the spleen that causes internal bleeding can be very serious as the spleen contains large amounts of blood.