Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues.
Different types of anemia include:
Iron deficiency anemia is the most common type of anemia.
Although many parts of the body help make red blood cells, most of the work is done in the bone marrow. Bone marrow is the soft tissue in the center of bones that helps form all blood cells.
Healthy red blood cells last between 90 and 120 days. Parts of your body then remove old blood cells. A hormone called erythropoietin (epo) made in your kidneys signals your bone marrow to make more red blood cells.
Hemoglobin is the oxygen-carrying protein inside red blood cells. It gives red blood cells their color. People with anemia do not have enough hemoglobin.
The body needs certain vitamins, minerals, and nutrients to make enough red blood cells. Iron, vitamin B12, and folic acid are three of the most important ones. The body may not have enough of these nutrients due to:
Possible causes of anemia include:
You may have no symptoms if the anemia is mild or if the problem develops slowly. Symptoms that may occur first include:
If the anemia gets worse, symptoms may include:
The provider will perform a physical examination, and may find:
Some types of anemia may cause other findings on a physical exam.
Blood tests used to diagnose some common types of anemia may include:
Other tests may be done to find medical problems that can cause anemia.
Treatment should be directed at the cause of the anemia, and may include:
Severe anemia can cause low oxygen levels in vital organs such as the heart, and can lead to heart failure.
Contact your provider if you have any symptoms of anemia or unusual bleeding.
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Lin JC. Approach to anemia in the adult and child. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 34.
Means RT. Approach to the anemias. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 149.
Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.