Why is the spleen called the “graveyard of red blood cells”?

The spleen is often called the “graveyard of red blood cells” because it is where old, worn-out, or damaged red blood cells (RBCs) are broken down and removed from circulation. Think of the spleen as a recycling center rather than just a graveyard—it filters blood, identifies weak or defective RBCs, and breaks them down to reuse their components.

Red blood cells have a lifespan of about 120 days. As they age, their membranes become less flexible and more fragile. When these cells pass through the narrow, maze-like spaces in the spleen called the splenic sinusoids, only healthy and flexible RBCs can squeeze through and return to the bloodstream. The old or damaged ones get trapped and are destroyed by immune cells known as macrophages inside the spleen.

During this process, the hemoglobin inside the RBCs is broken down. The iron is recycled and sent to the bone marrow to make new RBCs, while the rest of the hemoglobin molecule is converted into bilirubin, which later leaves the body through bile.

So, the spleen isn’t just a “graveyard.” It’s a smart organ that cleans and renews your blood supply, ensuring that only healthy, functional RBCs circulate through your body. Without this process, old or damaged RBCs would build up and interfere with normal blood function.