Ferritin is a protein in the cells of the body that stores iron. Doctors can take a blood sample and test your ferritin level to better understand how much iron your body is storing and to determine whether your ferritin level needs to be adjusted. A level that is too low points to an iron deficiency. If your ferritin level is too high, this could indicate liver disease, rheumatoid arthritis, hyperthyroidism or inflammatory diseases. If you have excess iron in your body, a condition known as hemochromatosis, you can take natural steps to reduce your ferritin level.