Iron deficiency anemia

Definition

Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. There are many types and causes of anemia.

Iron deficiency anemia occurs when your body does not have enough iron. Iron helps make red blood cells. Iron deficiency anemia is the most common form of anemia.

Alternative Names

Anemia - iron deficiency

Causes

Red blood cells bring oxygen to your body's tissues. 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, such as your spleen, remove old blood cells.

Iron is a key part of red blood cells. Without iron to make hemoglobin, your blood cannot carry oxygen effectively. Your body normally gets iron through your diet. It also reuses iron from old red blood cells.

Iron deficiency anemia develops when your body's iron stores run low. This can occur because:

Bleeding can cause iron loss. Common causes of bleeding are:

Your body may not absorb enough iron in your diet due to:

You may not get enough iron in your diet if:

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:

As the anemia gets worse, symptoms may include:

Symptoms of the conditions associated with bleeding that cause iron deficiency anemia include:

Exams and Tests

To diagnose anemia, your health care provider may order these blood tests:

To check iron levels, your provider may order:

To check for causes of blood loss, your provider may order:

Treatment

Treatment may include taking iron supplements and eating iron-rich foods.

Iron supplements (most often ferrous sulfate) build up the iron stores in your body. Most of the time, your provider will measure your iron level before you start 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 diet.

Often your anemia will improve or resolve with 6 weeks of iron therapy. You will need to keep taking iron for another 6 months to replace your body's iron stores in your bone marrow.

Iron supplements are mostly well tolerated, but may cause:

Iron-rich foods include:

Other sources include:

Vitamin C helps your body to absorb iron. Good sources of vitamin C are:

Outlook (Prognosis)

With treatment, the outcome is likely to be good, but it does depend on the cause.

When to Contact a Medical Professional

Contact your provider if:

Prevention

A balanced diet should include enough iron. Food sources of iron are listed above. If advised by your provider, take iron supplements.

References

Camaschella C. Disorders of iron homeostasis: iron deficiency and overload. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 37.

Elghetany MT, Banki K. Erythrocytic disorders. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 33.

Means RT Jr. Approach to the anemias. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 144.

National Heart, Lung, and Blood Institute website. Iron-deficiency anemia. www.nhlbi.nih.gov/health/anemia/iron-deficiency-anemia. Updated March 24, 2022. Accessed February 1, 2024.



Review Date: 4/18/2023
Reviewed By: John Roberts, MD, Professor of Internal Medicine (Medical Oncology), Yale Cancer Center, New Haven, CT. He is board certified in Internal Medicine, Medical Oncology, Pediatrics, Hospice and Palliative Medicine. Review provided by VeriMed Healthcare Network. Internal review and update on 02/03/2024 by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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