Iron deficiency anemia
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Anemia is a condition in which the body does not have enough healthy red blood cells. Iron helps make red blood cells.
When your body does not have enough iron, it will make fewer red blood cells or red blood cells that are too small. This is called iron deficiency anemia.
Anemia - iron deficiency
Causes, incidence, and risk factors
Iron deficiency anemia is the most common form of anemia.
Red blood cells bring oxygen to the body's tissues. Healthy red blood cells are made in your bone marrow. Red blood cells circulate through your body for 3 to 4 months. Parts of your body like your spleen remove old blood cells.
Iron is a key part of red blood cells. Without iron, the blood cannot carry oxygen effectively. Your body normally gets iron through your diet. It also reuses iron from old red blood cells.
You get iron deficiency anemia when your body's iron stores run low. This can occur because:
You lose more blood cells and iron than your body can replace
Your body does not do a good job of absorbing iron
Your body is able to absorb iron, but you are not eating enough foods that contain iron.
Your body needs more iron than normal (such as if you are pregnant or breastfeeding)
Bleeding can cause iron loss. Common causes of bleeding are:
Heavy, long, or frequent menstrual periods
Cancer in the esophagus, stomach, or colon
The use of aspirin, ibuprofen, or arthritis medicines for a long time, which can cause gastrointestinal bleeding
The body may not absorb enough iron in your diet due to:
You may not get enough iron in your diet if:
- You are a strict vegetarian
- You are an older adult and do not eat a full diet
You may have no symptoms if the anemia is mild.
Most of the time, symptoms are mild at first and develop slowly. Symptoms may include:
As the anemia gets worse, symptoms may include:
Symptoms of the conditions that cause iron deficiency anemia include:
Dark, tar-colored stools or blood
Heavy menstrual bleeding (women)
Pain in the upper belly (from ulcers)
Weight loss (in people with cancer)
Signs and tests
To diagnose anemia, your doctor may order these blood tests:
Tests to check iron levels in your blood include:
Tests that may be done to look for the cause of iron deficiency:
Before treatment, you and your health care provider must first search for the cause of your anemia. Next, the reason for iron deficiency needs to be discovered.
Treatment may include taking
Iron supplements (most often ferrous sulfate) are needed to build up the iron stores in your body. Most of the time, your doctor or nurse will measure your iron levels before starting supplements.
If you cannot take iron by mouth, you may need to take it through a vein (intravenous) or by an injection into the muscle.
Pregnant and breastfeeding women will need to take extra iron because they often cannot get enough iron from their normal diets.
Your hematocrit should return to normal after 2 months of iron therapy. You will need to keep taking iron for another 6 - 12 months to replace the body's iron stores in the bone marrow.
Iron-rich foods include:
Other sources include:
Raisins, prunes, and apricots
Spinach, kale, and other greens
With treatment, the outcome is likely to be good. However, it does depend on the cause.
Calling your health care provider
Call your health care provider if:
A well rounded diet should include enough iron. Red meat, liver, and egg yolks are high sources of iron. Flour, bread, and some cereals are fortified with iron. Take iron supplements if you aren't getting enough iron in your diet (uncommon in the United States).
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Mabry-Hernandez IR. Screening for iron deficiency anemia--including iron supplementation for children and pregnant women. Am Fam Physician. 2009 May 15;79(10):897-8.
Alleyne M, Horne MK, Miller JL. Individualized treatment for iron-deficiency anemia in adults. Am J Med. 2008;121:943-948..
- Last reviewed on 3/3/2013
- Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.
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This page was last updated: May 20, 2014