Red blood cells are the most prevalent form of blood cell. RBCs are shaped like a biconcave disc. A genetic abnormality can cause RBCs to become brittle and sickle-shaped (mutation).
A mature RBC has just 120 days before it is destroyed in the spleen (the graveyard of RBC ). The spleen has a structure similar to a large lymph node and mostly functions as a blood filter. The spleen is involved in both the formation of red blood cells (erythrocytes) and the digestive system.
Because old and damaged RBCs are eliminated in the spleen, it is known as the RBCs Graveyard.