– A chronic anemia characterized by depleted iron stores and small, pale red blood cells lacking in hemoglobin.
Causes and Incidence
Iron deficiency anemia is usually caused by chronic blood loss or by an increased need for or decreased intake of iron. It is the most common of the anemias, with a high worldwide incidence. It occurs most often in women, children, and the elderly in underdeveloped countries.
Some factor (e.g., chronic blood loss, a decrease in iron intake) leads to iron deficiency. This occurs in orderly steps. Initially, iron loss exceeds intake, and the iron stores in the bone marrow are used and depleted. A compensatory mechanism increases absorption of dietary iron but depletion continues, and insufficient iron is available for RBC formation. This leads to a decrease in Hgb production, microcytosis, and a decrease in oxygenation of the tissues.
Usual signs and symptoms associated with anemia (pallor, fatigue, weakness) plus symptoms specific to the iron deficiency, such as glossitis, cheilosis, koilonychia (spoon-shaped fingernails), and pica.
Exhaustion, infection, and respiratory and cardiac complications are possible if the condition goes untreated.
Decreased RBCs, Hgb, and Hct.
Peripheral blood smear
Decreased mean corpuscular volume and mean corpuscular Hgb concentration; microcytosis; hypochromia.
Decreased serum iron, serum ferritin, and iron ferritin; increased iron-binding capacity.
Bone marrow aspiration
Erythrocyte: granulocyte ratio 1:1 (normal, 1:3-1:5); lack of marrow iron; ringed sideroblasts.
Surgery – None.
Drugs – Iron replacement PO or parenterally.
Correction of underlying cause (e.g., treatment of bleeding, increased dietary intake of iron); nutritional education.