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Understanding Anemia -- the Basics

What Is Anemia?

Anemia is a condition that develops when your blood lacks enough healthy red blood cells. These cells are the main transporters of oxygen to organs. If red blood cells are also deficient in hemoglobin, then your body isn't getting enough oxygen. Symptoms of anemia -- like fatigue -- occur because organs aren't getting what they need to function properly.

gas exchange in the lungs

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 a form of anemia called iron-deficiency anemia because of the blood loss from menstruation and the increased blood supply demands during pregnancy.
Seniors 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:

Gastrointestinal conditions such as ulcers, hemorrhoids, gastritis (inflammation of the stomach), and cancer
Use of nonsteroidal anti-inflammatory drugs (NSAIDS) such as aspirinor ibuprofen
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

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 the 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
Iron deficiency anemia
Vitamin deficiency
Bone marrow and stem cell problems
Other health conditions

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 cells also get stuck in tiny blood vessels, causing pain.