Iron-deficiency Anemia

Iron-deficiency is a decrease in the number of red blood cells caused by inadequate stores of iron in the body. Iron is the central component of hemoglobin, the pigment in red blood cells which transports oxygen through the body. When the iron supply in the body is inadequate, hemoglobin production falls and anemia results.

Causes

Iron deficiency is the most common cause of anemia. It is estimated to occur in one out of five nonpregnant women of childbearing age, in one out of two pregnant women, and in three out of 100 men. The principal causes of the disease are inadequate iron in the diet, insufficient iron absorption during digestion, and abnormal blood loss. Women are particularly prone to developing the disease because of blood loss during menstruation. Pregnancy is also associated with iron deficiency since the mother is producing blood cells for the fetus as well as for herself. Lactation also increases the need for iron, which is a component of breast milk. In women after menopause and in men, the most likely cause of iron deficiency anemia is blood loss in the digestive tract from conditions such as ulcers, colon polyps, or colon cancer or the use of aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen. In children, lead poisoning can interfere with iron utilization and cause anemia. Children and adolescents sometimes become iron deficient during periods of accelerated growth, when demand for iron exceeds intake. Vegetarians, who eat no animal products (vegans) for a period of several years, have an increased likelihood of developing iron deficiency anemia.

Symptoms and Diagnosis

Mild iron deficiency anemia often produces no symptoms. If the disease progresses, symptoms appear, which include pallid skin, fatigue, irritability, weakness, shortness of breath, postural hypotension (low blood pressure on standing up), brittle nails, headache, and a sore tongue. Some people develop cravings for nonfood items such as clay, soil, and ice, a condition called PICA. Children are likely to experience a decreased appetite.

Iron deficiency anemia is diagnosed by blood tests that measure the amount of hemoglobin and iron in the blood. If the iron deficiency is thought to be the result of digestive tract bleeding, other tests may be performed to identify the bleeding site.

Treatment and Prevention

Iron deficiency anemia is treated by increasing dietary iron intake and by taking supplemental iron, typically in the form of ferrous sulfate. Iron-rich foods include red meat, raisins, fish, egg yolks, liver, poultry, legumes (peas and beans), potatoes, and whole grains. Occasionally, people with iron deficiency anemia are given supplemental iron by injection. In severe cases, blood transfusions may be given until the bone marrow can replace the blood that has been lost. In most cases, the iron level in the blood comes up to normal in about two months. Therapy is continued for another 6 to 12 months to rebuild the stores of iron in the bone marrow. If bleeding from the digestive tract causes the anemia, the underlying condition needs to be treated to prevent continued blood loss.

Iron deficiency anemia can be prevented by eating a healthy diet and taking iron supplements when at increased risk for the disease. Those at risk are menstruating women, pregnant women, children and adolescents, and vegetarians.

Source: AMA Complete Encyclopedia, Copyright 2003, American Medical Association
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