According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), there are three main kinds of hemochromatosis:
Primary, or hereditary, hemochromatosis: A genetic mutation to the HFE gene usually causes this type.
Secondary hemochromatosis: Too much iron from blood transfusions or a high iron diet causes this type.
Neonatal hemochromatosis: This type occurs in a fetus when the liver is damaged in the womb, causing excess iron to build up.