What is a ferritin blood test?A ferritin blood test measures the level of ferritin in your blood. Ferritin is a protein that stores iron inside your cells. You need iron to make healthy red blood cells. Red blood cells carry oxygen from your lungs to the rest of your body. Iron is also important for healthy muscles, bone marrow, and organ function. Too little or too much iron in your system can cause serious health problems if not treated.Other names: serum ferritin, serum ferritin level, ferritin serum
