Red blood cells (RBCs)

October 27, 2023

Normal red blood cells

Red blood cells (RBCs) are a type of blood cell that carries oxygen from your lungs to the rest of your body and carbon dioxide back to the lungs. They hold onto oxygen and carbon dioxide using a specialized protein called hemoglobin.

RBCs are made in a part of the bone called the bone marrow. As young RBCs mature in the bone marrow, they produce hemoglobin. Your body needs iron in order to make hemoglobin for RBCs. Once this process is complete, the RBCs are released into the bloodstream. Normal, healthy RBCs circulate in the bloodstream for about 120 days before they are removed, and their iron is recycled to make new RBCs.

Extra iron is stored in a specialized protein called ferritin. The amount of ferritin will change as the amount of iron in your body changes. For example, a person with low levels of iron in their body will have low levels of ferritin in their blood.

Medical conditions associated with red blood cells

Other helpful resources

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