Spleen vs. No Spleen

The spleen is an organ in the upper far left part of the abdomen, to the left of the stomach. It varies in size and shape between people, but is commonly fist-shaped, purple, and about four inches long. Because the spleen is protected by the rib cage, you cannot easily feel it unless it is abnormally enlarged. About 10% of people have a small extra accessory spleen, which causes no problems and is considered normal.

The spleen plays multiple supporting roles in the body. It acts as a filter for blood as part of the immune system. Old red blood cells are recycled in the spleen, and platelets and white blood cells are stored there. It also helps fight certain kinds of bacteria that cause pneumonia and meningitis.

Bottom line, the spleen filters blood and helps the body fight infections, but it is not essential for survival. The spleen can be removed if it is damaged. However, people without a spleen are more prone to infections.