American Medical Association Family Medical Guide - American Medical Association [363]
A shortage of iron in the body has a number of possible causes. In most people who have iron deficiency anemia, stored iron has been depleted by excessive blood loss. For example, women who have extremely heavy menstrual periods can deplete their supply of iron and develop anemia. (Women who have normal periods seldom have a problem maintaining an adequate supply of iron.) Blood loss from the intestinal tract can result from digestive system disorders such as gastroesophageal reflux disease (GERD; see page 750), a peptic ulcer (see page 755) or duodenal ulcer (see page 756), polyps (see page 773), or cancer of the colon (see page 775).
Some people may not take in enough iron in their diet to replace the iron they lose each day. This condition occurs mainly in young children, pregnant women, and people who are on a restricted diet. Sometimes a person’s digestive system is unable to absorb iron from food, no matter how much iron is in his or her diet. This problem occurs in some disorders of the small intestine that affect absorption of nutrients, such as celiac disease (see page 768), which blocks the absorption of gluten (a protein found in foods that contain wheat, rye, oats, or barley).
Symptoms
Initial symptoms of iron deficiency anemia often are so mild that they go unnoticed. Symptoms can include abnormally pale skin, weakness, fatigue, faintness, or shortness of breath. A person may have palpitations (heartbeats that you’re aware of) when his or her heart tries to compensate for decreased blood flow by pumping blood at a faster rate. The person may have a sore, inflamed tongue; headaches; a poor appetite; and an increased susceptibility to infection. Some people with anemia may also experience restless legs syndrome (see page 705), perhaps resulting from impaired blood flow to the legs. They may be unable to keep their legs still, and sometimes may experience a tingling or crawling sensation in their legs.
Diagnosis
If you have symptoms of iron deficiency anemia, your doctor will examine you and order blood tests to evaluate the number, size, and color of the red cells in your blood and the amount of hemoglobin they contain. (Iron-deficient red cells are smaller and paler than normal red cells.) The doctor also will order tests to help determine if an underlying disease is causing the anemia. In most cases, a doctor may order a blood test to measure the level of the protein ferritin. Because ferritin helps the body store iron, a low level of ferritin in the blood indicates a low level of iron. You will probably have tests to measure the amount of iron and vitamin B12 in your blood, and a test to check for blood in your stool. If blood is detected in your stool, you may have additional tests, such as colonoscopy (see page 767), an examination of the rectum and large intestine.
A bone marrow biopsy is sometimes recommended to evaluate the body’s iron reserves and to determine the cause of anemia. A bone marrow biopsy is done by passing a hollow needle into a bone—such as the back of the pelvic bone—and removing a small sample of marrow from inside the bone. Local anesthesia is used for the procedure. A bone marrow biopsy can confirm or rule out iron deficiency. It can also help determine other causes of poor red blood cell production, including drug toxicity, lead poisoning, or bone marrow diseases such as multiple myeloma (see page 627), leukemia (see page 621), or aplastic anemia (see page 628).
Treatment
Doctors treat iron deficiency anemia by replacing the lost iron and treating the underlying condition that is causing the shortage of iron in the body. A doctor may prescribe iron supplements to take for several months or longer. (Take the supplements according to your doctor’s instructions to avoid indigestion or other gastrointestinal symptoms.) The iron may darken your stool, which is normal. If you have problems taking the supplements, your doctor may inject the iron into a muscle or vein. Iron deficiency anemia