Toenails often serve as barometers of our health; they are diagnostic tools providing the initial signal of the presence or onset of systemic diseases. For example, the pitting of nails and increased nail thickness can be manifestations of psoriasis. Concavity—nails that are rounded inward instead of outward—can foretell iron deficiency anemia. Some nail problems can be conservatively treated with topical or oral medications while others require partial or total removal of the nail. Any discoloration or infection on or about the nail should be evaluated by a podiatric physician.