Iron deficiency anemia occurs when the body’s usual stores of iron are so depleted that the bone marrow cannot produce enough hemoglobin, the iron-containing protein in red blood cells that carries oxygen in the bloodstream.

Iron deficiency is the most common cause of anemia, is rarely serious, and is easily treated in most cases. In fact, in mild chronic cases, it often produces few or no symptoms and is generally discovered only when a doctor obtains a complete blood count (CBC). Of course, more severe anemia gradually leads to noticeable fatigue and other symptoms.

What Causes Iron Deficiency Anemia?

  • The most common cause of iron deficiency anemia is gradual, prolonged blood loss. For this reason, menstruating women are particularly prone to anemia. In men, the most common cause of iron deficiency is blood loss in the digestive tract, resulting from disorders such as peptic ulcer, inflammatory bowel disease, and stomach or colon cancer. Sometimes hemorrhoids bleed enough to result in anemia.
  • Long-term use of aspirin (for heart attack prevention) or nonsteroidal anti-inflammatory drugs (such as ibuprofen and naproxen, used for pain relief) can irritate the lining of the stomach and cause bleeding, resulting in anemia.
  • Pregnancy and breastfeeding increase the susceptibility of iron deficiency. Children with an inadequate diet may also be at risk.
  • In chronically ill patients, repeated blood drawing for diagnostic testing can produce an iron deficiency.
  • Poor absorption of iron may result from surgical removal of the stomach (gastrectomy), from intestinal disorders that cause chronic diarrhea, or from abnormal food habits such as the ingestion of clay (stemming from unusual cravings known as pica), which can bind to iron.
  • Intestinal bacteria or parasites such as hookworm can cause iron deficiency.

Symptoms of Iron Deficiency Anemia

  • Fatigue and weakness
  • Pallor (paleness; may be especially noticeable in the gums, eyelids, and nail beds)
  • Heart palpitations, rapid heartbeat, or breathing difficulty, especially upon exertion
  • Irritability
  • Loss of appetite
  • Dizziness
  • Cold hands and feet and low body temperature
  • Hair loss
  • Headaches
  • Depression
  • Loss of interest in work and usual activities
  • Inability to concentrate
  • Smooth, sore tongue or tiny cracks at the corners of the mouth
  • Brittle nails
  • Black, tarry (or even bloody) stools (when anemia is due to substantial blood loss in the gastrointestinal tract)
  • Unusual craving (called pica) for clay, dirt, or ice


  • Eat a healthy, well-balanced diet.
  • Increase your intake of foods that are high in iron.
  • Pregnant and menstruating women should discuss iron supplementation with their doctors.
  • If you must regularly take aspirin or nonsteroidal anti-inflammatory drugs, take them with food or an antacid (one containing magnesium and aluminum hydroxide is best).

Diagnosis of Iron Deficiency Anemia

  • A blood test for the protein ferritin can usually determine whether there is an iron deficiency.
  • A gastrointestinal endoscopy, the insertion of a lighted scope through the mouth and into the esophagus or through the rectum and into the colon, may be necessary to locate the source of gastrointestinal iron loss.

How to Treat Iron Deficiency Anemia

  • It is essential for a doctor to determine the underlying cause of an iron deficiency, and each case is treated based on the doctor’s conclusions. Do not attempt to self treat iron deficiency anemia since iron deficiency is always caused by an underlying illness.
  • Iron supplementation may be required—but only under a doctor’s supervision. Taking too much iron unnecessarily can lead to excessive storage of iron and serious health problems, including heart and liver damage. Also, if you are losing blood due to a disease such as colon cancer, supplements might mask the problem and delay the diagnosis.
  • If iron supplements are prescribed, be sure to take them for the full term recommended by your doctor, even if you begin to feel well again. After the anemia is cured, your body needs to replenish its reserve stores of iron, which may take three months or more.
  • Note that absorption of medicinal iron is decreased by milk and antacids.
  • Iron may be given by intravenous injection in patients who cannot tolerate oral iron therapy.
  • In very rare and severe cases, iron deficiency anemia may be severe enough to require a transfusion of red cells.
  • Proper nutrition, including foods that are rich in iron, is important for children and adults. Good eating habits can help prevent iron deficiency and iron-deficiency anemia.

When to Call a Doctor

  • Call your doctor if you experience the symptoms of anemia. Sometimes iron deficiency anemia is an indication of a more serious underlying disorder, such as peptic ulcer or colon cancer. Certain tests may be needed to confirm or rule out these possibilities.
  • Women who are pregnant or menstruate heavily should contact their doctors to discuss supplementation with iron.
  • People on rapid weight loss programs should discuss their dietary needs for iron and other nutrients with a doctor or a qualified nutritionist.


Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference

Simeon Margolis, M.D., Ph.D., Medical Editor

Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Updated by Remedy Health Media

Publication Review By: the Editorial Staff at

Published: 16 Aug 2011

Last Modified: 02 Oct 2014