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What Is Iron-Deficiency Anemia?

Iron-deficiency anemia is a common and easily treated condition that occurs when there is not enough iron in the body. It is the most common type of anemia. A lack of iron in the body can come from bleeding, not eating enough foods that contain iron, or not absorbing enough iron from food that is eaten.


The term "anemia" (uh-NEE-me-uh) is used for a group of conditions in which the number of red blood cells in the blood is lower than normal, or the red blood cells don’t have enough hemoglobin (HEE-muh-glow-bin). Hemoglobin—an iron-rich protein that gives the red color to blood—carries the oxygen from the lungs to the rest of the body. In people with anemia, the blood does not carry enough oxygen to the rest of the body. Red blood cells also remove carbon dioxide, a waste product, from cells and carry it to the lungs to be exhaled.

Red blood cells also are called RBCs or erythrocytes (eh-RITH-roh-sites). Normal red blood cells are all about the same size and look like doughnuts without a hole in the center. They are produced by the spongy marrow inside the large bones of the body. Healthy red blood cells have an average lifespan of 120 days. When they die, the iron from the hemoglobin is recycled to make new red blood cells.

There are many types of anemia. The three major causes of anemia are blood loss, decreased production of red blood cells, or increased destruction of red blood cells. White blood cells and platelets are the two other kinds of blood cells. White blood cells help fight infection. Platelets help blood to clot. In some kinds of anemia, there are low amounts of all three types of blood cells. The most common symptom of all types of anemia is feeling tired because the body is not receiving enough oxygen.

Iron-Deficiency Anemia

In iron-deficiency anemia, the body does not have enough iron to form hemoglobin, which means there is not enough hemoglobin to carry oxygen to the whole body. The body gets its iron from food. The main foods that contain iron are meat and shellfish as well as iron-fortified foods (that is, foods that have iron added). A steady supply of iron is needed to form hemoglobin and healthy red blood cells.

A person can have low iron levels for three reasons:

  • Blood loss, either from disease or injury
  • Not getting enough iron in the diet
  • Not being able to absorb the iron in the diet

Iron-deficiency anemia also can develop when the body needs higher levels of iron, such as during pregnancy.

Effects of Iron-Deficiency Anemia on the Body

Iron-deficiency anemia can range from mild to severe. A mild case usually causes no symptoms or problems. However, a severe case can cause extreme fatigue (tiredness) and weakness. Severe iron-deficiency anemia can lead to serious problems for young children and pregnant women, and it can affect the heart.

In young children, iron-deficiency anemia can cause a heart murmur and delays in growth and development. It puts a child at greater risk for lead poisoning and infections, and it can cause behavior problems.

In pregnant women, iron-deficiency anemia can increase the risk of a premature delivery and a low-birth-weight baby.

The heart is affected when there is a lack of oxygen in the body. The heart has to work harder to get enough oxygen throughout the body. Over time, this stress on the heart can lead to a fast or irregular heartbeat, chest pain, an enlarged heart, and even heart failure.

Important General Information

A lack of iron in the body is the most common nutritional problem. Iron-deficiency anemia is the most common form of anemia. It is most often found in young children, pregnant women, and women of childbearing age. In fact, it affects half of all pregnant women and 1 out of 5 women of childbearing age.


Iron-deficiency anemia can be treated successfully. The causes of iron-deficiency anemia can most often be treated successfully as well. However, if not treated, it can lead to severe symptoms and serious problems.

May 2006


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