Anemia is a condition that develops when your blood lacks enough healthy red blood cells or hemoglobin. Hemoglobin is a main part of red blood cells and binds oxygen. If you have too few or abnormal red blood cells, or your hemoglobin is abnormal or low, the cells in your body will not get enough oxygen. Symptoms of anemia -- like fatigue -- occur because organs aren't getting what they need to function properly.
Anemia is the most common blood condition in the U.S. It affects about 3.5 million Americans. Women and people with chronic diseases are at increased risk of anemia. Important factors to remember are:
Certain forms of anemia are hereditary and infants may be affected from the time of birth.
Women in the childbearing years are particularly susceptible to iron-deficiency anemia because of the blood loss from menstruation and the increased blood supply demands during pregnancy.
Older adults also may have a greater risk of developing anemia because of poor diet and other medical conditions.
There are many types of anemia. All are very different in their causes and treatments. Iron-deficiency anemia, the most common type, is very treatable with diet changes and iron supplements. Some forms of anemia -- like the anemia that develops during pregnancy -- are even considered normal. However, some types of anemia may present lifelong health problems.
What Causes Anemia?
There are more than 400 types of anemia, which are divided into three groups:
Anemia caused by blood loss
Anemia caused by decreased or faulty red blood cell production
Anemia caused by destruction of red blood cells
Anemia Caused by Blood Loss
Red blood cells can be lost through bleeding, which can occur slowly over a long period of time, and can often go undetected. This kind of chronic bleeding commonly results from the following:
Use of nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirinor ibuprofen, which can cause ulcers and gastritis
Menstruation and childbirth in women, especially if menstrual bleeding is excessive and if there are multiple pregnancies
Anemia Caused by Decreased or Faulty Red Blood Cell Production
With this type of anemia, the body may produce too few blood cells or the blood cells may not function correctly. In either case, anemia can result. Red blood cells may be faulty or decreased due to abnormal red blood cells or a lack of minerals and vitamins needed for red blood cells to work properly. Conditions associated with these causes of anemia include the following:
Sickle cell anemia is an inherited disorder that affects African-Americans. Red blood cells become crescent-shaped because of a genetic defect. They break down rapidly, so oxygen does not get to the body's organs, causing anemia. The crescent-shaped red blood can cells also get stuck in tiny blood vessels, causing pain.