Ferritin levels are the amount of ferritin in the blood related to the amount of iron stored in the body, according to MedlinePlus. Ferritin levels are measured to identify likely causes of anemia, detect inflammation, or to determine whether there is excess iron in the body.
Ferritin is a protein that binds to iron and is found in the blood, liver, spleen and skeletal muscles, explains WebMD. Although blood contains the least amount of ferritin in the body, it is the main source used to test levels. If levels are high, the body could be storing too much iron. If the levels are low, it could indicate an iron deficiency. High ferritin levels can also indicate certain types of cancers, hyperthyroidism or liver disease, claims Mayo Clinic.