Measures the Ferritin blood protein in your blood.  Or what some will refer to as Iron Stores, or Stored Iron.

Iron is used in the bone marrow to produce new Red Blood Cells.

Low Levels, or Iron Deficiency, can lead to becoming anemic.

High levels could point to a hereditary disease (Homocystinuria), Inflammatory Conditions,  Rheumatoid Arthritis,  Hyperthyroidism, and some types of Cancer.