Definition of Iron deficiency anemia:

Anemia is a condition in which the body does not have enough healthy red blood cells. Iron is an important building block for 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.

See also:

• Anemia
• Iron deficiency anemia - children

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 move through your body for 3 to 4 months. Parts of your body then 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 and by re-using iron from old red blood cells.

You get iron deficiency anemia when your body's iron stores run low. You can get iron deficiency if:

• 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 with iron in them
• Your body needs more iron than normal (such as if you are pregnant or breastfeeding)

Iron loss can be due to bleeding. Common causes of bleeding are:

• Heavy, long, or frequent menstrual periods
• Cancer in the esophagus, stomach, or colon
• Esophageal varices
• The use of aspirin, ibuprofen, or arthritis medicines for a long time
• Peptic ulcer disease

The body may not absorb enough iron in the diet due to:

• Celiac disease
• Crohn's disease
• Gastric bypass surgery
• Taking too many antacids that contain calcium

You may not get enough iron in the diet if:

• You are a strict vegetarian
• You are an older adult and do not eat a full diet

Symptoms:

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:

• Feeling grumpy
• Feeling weak or tired more often than usual, or with exercise
• Headaches
• Problems concentrating or thinking

As the anemia gets worse, symptoms may include:

• Blue color to the whites of the eyes
• Brittle nails
• Light-headedness when you stand up
• Pale skin color
• Shortness of breath
• Sore tongue

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:

• Hematocrit and hemoglobin (red blood cell measures)
• RBC indices

Tests to check iron levels in your blood include:

• Bone marrow exam (rare)
• Iron binding capacity (TIBC) in the blood
• Serum ferritin
• Serum iron level

Tests that may be done to look for the cause of iron deficiency:

• Colonoscopy
• Fecal occult blood test
• Upper endoscopy

Treatment:

Taking supplements and eating iron-rich foods are important parts of treating iron deficiency anemia. However, you and your health care provider must first search for the cause of your anemia.

Iron supplements (most often ferrous sulfate) are needed to build up the iron stores in your body.

Patients who cannot take iron by mouth can take it through a vein (intravenous) or by an injection into the muscle.

Pregnant and breastfeeding women will need to take extra iron because their normal diet usually will not provide the amount they need.

The hematocrit should return to normal after 2 months of iron therapy. However, keep taking iron for another 6 - 12 months to replace the body's iron stores in the bone marrow.

Iron-rich foods include:

• Chicken and turkey
• Dried lentils, peas, and beans
• Eggs (yolk)
• Fish
• Meats (liver is the highest source)
• Peanut butter
• Soybeans
• Whole-grain bread

Other sources include:

• Oatmeal
• Raisins, prunes, and apricots
• Spinach, kale, and other greens

Expectations (prognosis):

With treatment, the outcome is likely to be good. However, it does depend on the cause. Usually, blood counts will return to normal in 2 months.

Calling your health care provider:

Call for an appointment with your health care provider if:

• You have symptoms of this disorder
• You notice blood in your stool

Prevention:

Everyone's diet should include enough iron. Red meat, liver, and egg yolks are important sources of iron. Flour, bread, and some cereals are fortified with iron. If you aren't getting enough iron in your diet (uncommon in the United States), take iron supplements.

During periods when you need extra iron (such as pregnancy and breastfeeding), increase the amount of iron in your diet or take iron supplements.