Iron deficiency anemia is a low red blood cell count or hemoglobin level caused by too little iron in the body. Hemoglobin is a molecule in the red blood cells that carries oxygen to cells throughout the body.
Though anemia has many causes, iron deficiency is the most common. Iron is a very important part of the hemoglobin molecule. When the body does not have enough iron stored, too little hemoglobin is made to fill the red blood cells. The size and number of red blood cells decreases. This cuts down on the body's ability to carry oxygen to the tissues.
Iron deficiency anemia occurs when iron intake cannot keep pace with iron loss. This can be due to:
Women of childbearing age, pregnant women, children, and teens are at the greatest risk for this condition.
Iron deficiency anemia doesn't cause symptoms right away. The symptoms, which develop slowly over time, may include the following:
Diagnosis of iron deficiency anemia starts with a medical history and physical exam. Blood tests, including a complete blood count or CBC, may be ordered. Further tests may be needed to determine the reason for the low iron if it is not clear. For example, screening tests for colon cancer can detect blood in the stool.
A bone marrow biopsy may be done in complex cases. The biopsy involves inserting a special needle through the skin into the hipbone. A sample of bone marrow is then taken with the needle. Bone marrow is a soft substance in the middle of some bones. Red blood cells are made in the marrow. Much of the body's iron is stored inside the bone marrow. A sample of bone marrow can be examined to look for iron deficiency.
Many cases of iron deficiency anemia can be prevented by eating a diet rich in iron or taking iron supplements. Some of the foods that are high in iron are as follows:
Almost all problems caused by iron deficiency anemia can be reversed with treatment. However, if the anemia is severe and other health problems exist, it can lead to:
Iron deficiency anemia is not contagious. It poses no risk to others.
The first step in treatment for iron deficiency anemia is to find and correct the reason for low iron levels. For example, the source of blood loss may need to be identified. Iron stores are then replaced. If a person does not have a problem absorbing iron, this can be done through a diet rich in iron or iron supplements. Iron is best absorbed on an empty stomach.
The individual should follow these dietary guidelines to increase iron stores in the body.
Even when the body is healthy, it does not take in iron very well. Because of that, a person may be advised to take iron supplements for several months to a year. Iron should be taken as prescribed by the healthcare provider. If oral iron supplements fail, iron can be given intravenously or through shots into a muscle.
Iron supplements may cause nausea, diarrhea, heartburn, or constipation. Iron poisoning can occur with an overdose of iron pills. When iron is given into a vein or muscle, the healthcare provider will need to monitor the person closely. Taking iron this way can cause:
With treatment for iron deficiency anemia, most people can return to normal activities as soon as they desire. Lifelong iron replacement is usually not necessary. The exact treatment and when it may end often depends on the underlying cause as well. For example, some people have colon cancer that has caused blood loss. This may require intensive treatment with surgery and chemotherapy.
After treatment for iron deficiency anemia is finished, blood tests are done to make sure iron stores have been replaced. Any new or worsening symptoms should be reported to the healthcare provider.
Author:Thomas Fisher, MD
Date Written:
Editor:Ballenberg, Sally, BS
Edit Date:07/31/01
Reviewer:Kimberly A. Tessmer, RD, LD
Date Reviewed:06/26/01
Mahan, K, MS, RD, CDE & Escott-Stump, S., MA, RD, LDN. (2000). Krause's Food, Nutrition, & Diet Therapy (10th ed.). Pennsylvania: W.B. Saunders Company.
Somer, E., MA, RD. & Health Media of America. (1995). The Essential Guide To Vitamins and Minerals (2nd ed.). New York: HarperCollins Publishers, Inc.
Duyff, R., MS, RD, CFCS. (1996). The American Dietetic Association's Complete Food & Nutrition Guide. Minnesota: Chronimed Publishing.