Anemia

What is anemia?

Anemia is a blood disorder that is defined as:

• not having enough red blood cells (RBCs), or
• not having enough hemoglobin.

Hemoglobin is the part of red blood cells that carries oxygen. When you have fewer red blood cells than normal or too little hemoglobin, the blood is not able to carry enough oxygen to all parts of the body.

Some different kinds of anemia are:

• iron deficiency anemia
• hemolytic anemia
• vitamin B-12 deficiency anemia
• folic acid deficiency anemia
• anemia caused by inherited blood diseases (for example, sickle cell anemia and thalassemia)
• anemia caused by chronic (ongoing) disease, such as rheumatoid arthritis.

How do the different forms of anemia occur?

Iron deficiency anemia

This most common form of anemia results from not having enough iron in the blood. Your blood cells need iron to make hemoglobin. Iron deficiency anemia may be caused by a lack of iron in the diet or a loss of blood. Pregnant women may have this form of anemia because the baby uses the mother's iron to make red blood cells and to grow. Women lose blood during their menstrual periods. Another cause of blood loss may be internal bleeding in the stomach or in the intestine.

Hemolytic anemia

This kind of anemia occurs when red blood cells are destroyed or damaged by infection, drugs, or inherited conditions.

Vitamin B-12 (cobalamin) deficiency anemia

This type of anemia results when the stomach or intestines have trouble absorbing vitamin B-12. For example, an immune system disorder called pernicious anemia prevents normal absorption of vitamin B-12. Stomach or intestinal illness, some medicines, and some inherited problems may also cause vitamin B-12 deficiency. Some vegetarians may not get enough vitamin B-12 from the foods they eat.

Besides causing anemia, a lack of vitamin B-12 affects the nervous system. It may cause symptoms of numbness, tingling, balance problems, depression, or memory problems.

Folic acid deficiency anemia

Anemia due to a lack of folic acid in the diet is similar to B-12 deficiency anemia, but it does not damage nerves. However, it can cause depression. Not enough folic acid in a woman's diet at the time she becomes pregnant or during early pregnancy can cause birth defects. This type of anemia is common in:

• pregnant women
• people whose intestines have problems absorbing nutrients from food
• people who use some medicines every day, such as phenytoin, sulfasalazine, and possibly birth control pills
• alcoholics.

Anemia caused by inherited problems with red blood cells

Two common types of inherited problems--sickle cell anemia and thalassemia--cause abnormal red blood cells.

• Sickle cell anemia causes abnormal, sickle-shaped red blood cells. Sickle cell disease is most common among people who are African, African American, Mediterranean (Italian or Greek), Middle Eastern, East Indian, Caribbean, and Central or South American. The abnormal RBCs are damaged or destroyed as they pass through the circulatory system. The anemia causes many symptoms. It can cause a condition called sickle cell crisis. A crisis may happen under certain conditions such as altitude or pressure changes, low oxygen, or some illnesses. In sickle cell crisis the RBCs become even more deformed. The deformed cells block tiny blood vessels, causing severe, prolonged pain and other complications.
• Thalassemias are a group of anemias caused by abnormal hemoglobin. The abnormal hemoglobin may cause abnormal red blood cells as well as low hemoglobin levels. Thalassemias most often affect people of Mediterranean descent. Some types also affect peoples of Africa, Asia, India, and the South Pacific. Most forms of thalassemia are mild, but some forms cause life-threatening disease in children.

Anemia caused by disease

Some of the ongoing (chronic) diseases that may cause anemia are:

• cancer
• rheumatoid arthritis
• ongoing infections
• kidney disease.

What are the symptoms?

Mild anemia usually does not cause symptoms.

Symptoms of more severe anemia may include:

• weakness
• tiredness
• pale skin, gums, and nail beds.

Symptoms of worsening anemia include:

• lightheadedness, especially when you change positions, for example, when you stand up
• fast heartbeat
• shortness of breath
• fainting
• chest pain.

Jaundice (yellow skin and eyes) may be a symptom of hemolytic anemia.

How is it diagnosed?

Your healthcare provider will carefully review your symptoms and examine you. You will have a complete blood count (CBC). The CBC can show how severe the anemia is. You may need other tests to determine the type of anemia.

How is it treated?

The treatment depends on the type of anemia you have.

To treat iron deficiency anemia (if there is no underlying disease causing blood loss), your healthcare provider may simply prescribe iron supplements and/or a diet of foods rich in iron.

If you have vitamin B-12 deficiency anemia because your stomach does not absorb vitamin B-12 well, the usual treatment is a shot of vitamin B-12 once a month. In some cases your healthcare provider may prescribe an oral tablet.

The treatment for folic acid deficiency anemia is daily oral folate tablets. This anemia is similar to vitamin B-12 deficiency anemia. You should not start taking folate supplements until your healthcare provider has made sure you do not have vitamin B-12 deficiency anemia.

Sickle cell anemia usually requires frequent treatments. Sickle cell crisis requires IV (intravenous) fluids, rest, pain relief, and sometimes a blood transfusion.

The treatment for thalassemia depends on the severity of the anemia and your age. If you need a blood transfusion, there is a very small risk that you will get a blood-borne disease such as hepatitis or AIDS, even though donated blood is carefully screened. For this reason, your healthcare provider will recommend a transfusion only when it is clearly the best treatment for you. People who have thalassemia must not take iron tablets.

Fortunately, the effects of anemia caused by chronic disease usually tend to be mild. For certain conditions, such as chronic kidney disease, your healthcare provider may prescribe regular shots of erythropoietin. These shots cause your body to make more red blood cells.

You will have follow-up visits with your healthcare provider to check your blood count and the effects of your treatment.

How long will the effects last?

The symptoms of mild, easily treated anemias, such as iron deficiency anemia, respond quickly to treatment and get better in just a few days.

The symptoms of chronic anemias, such as sickle cell anemia, come and go. Anemia associated with a chronic disease usually gets better or worse as the disease improves or worsens.

How can I take care of myself?

Follow your healthcare provider's instructions. Take your medicine as prescribed.

What can I do to help prevent anemia and problems it causes?

The prevention of anemia depends on the cause. If your anemia is caused by a deficiency in your diet, eating foods rich in the missing nutrient will help stop it from coming back.

To prevent the complications of vitamin B-12 deficiency anemia, follow your healthcare provider's treatment of vitamin B-12 shots.

If you have sickle cell disease, it is important not to get dehydrated (that is, not to lose too much body fluid) during hot weather, exercise, or illness. Dehydration can trigger a sickle cell crisis.

Genetic counseling is important for families with inherited anemia.