Anemia is a medical condition in which the red blood cell count or hemoglobin is less than normal. The normal level of hemoglobin is generally different in males and females. For men, anemia is typically defined as hemoglobin level of less than 13.5 gram/100ml and in women as hemoglobin of less than 12.0 gram/100ml. These definitions may vary slightly depending on the source and the laboratory reference used.
Causes of Anemia
Many medical conditions cause anemia. Common causes of anemia include the following:
* Anemia from active bleeding: Loss of blood through heavy menstrual bleeding or, wounds can cause anemia. Gastrointestinal ulcers or cancers such as cancer of the colon may slowly ooze blood and can also cause anemia.
* Iron deficiency anemia: The bone marrow needs iron to make red blood cells. Iron plays an important role in the proper structure of the hemoglobin molecule. If iron intake is limited or inadequate due to poor dietary intake, anemia may occur as a result. This is called iron deficiency anemia.
* Anemia of chronic disease: Any long-term medical condition can lead to anemia. The exact mechanism of this process in unknown, but any long-standing and ongoing medical condition such as an infection or a cancer may cause this type of anemia.
* Anemia related to kidney disease: The kidneys release a hormone called the erythropoietin that helps the bone marrow make red blood cells. In people with chronic (long-standing) kidney disease, the production of this hormone is diminished, and this in turn diminishes the production of red blood cells, causing anemia. This is called anemia related to chronic kidney disease.
* Anemia related to pregnancy: Water weight gain during pregnancy dilutes the blood, which may be reflected as anemia.
* Anemia related to poor nutrition: Vitamins and minerals are required to make red blood cells. In addition to iron, vitamin B12 and folate are required for the proper production of hemoglobin. Deficiency in any of these may cause anemia because of inadequate production of red blood cells. Poor dietary intake is an important cause of low folate and low vitamin B12 levels. Strict vegetarians who do not take sufficient vitamins are at risk to develop vitamin B12 deficiency.
* Pernicious Anemia: There also may be a problem in the stomach or the intestines leading to poor absorption of vitamin B12. This may lead to anemia because of vitamin B12 deficiency known as pernicious anemia.
* Sickle cell anemia: In some individuals, the problem may be related to production of abnormal hemoglobin molecules. In this condition the hemoglobin problem is qualitative, or functional. Abnormal hemoglobin molecules may cause problems in the integrity of the red blood cell structure and they may become crescent-shaped (sickle cells). There are different types of sickle call anemia with different severity levels. This is typically hereditary and is more common in those of African, Middle Eastern, and Mediterranean ancestry.
* Thalassemia: this is another group of hemoglobin-related causes of anemia. There are many types of thalassemia, which vary in severity. These are also hereditary, but they cause quantitative hemoglobin abnormalities, meaning an insufficient number of hemoglobin molecules is made.
* Alcoholism: Poor nutrition and deficiencies of vitamins and minerals are associated with alcoholism. Alcohol itself may also be toxic to the bone marrow and may slow down the red blood cell production. The combination of these factors may lead to anemia in alcoholics.
* Bone marrow-related anemia: Anemia may be related to diseases involving the bone marrow. Some blood cancers such as leukemia or lymphomas can alter the production of red blood cells and result in anemia. Other processes may be related to a cancer from another organ spreading to the bone marrow.
* Aplastic anemia: Occasionally some viral infections may severely affect the bone marrow and diminish production of all blood cells. Chemotherapy (cancer medications) and some other medications may pose the same problems.
* Hemolytic anemia: The normal red blood cell shape is important for its function. Hemolytic anemia is a type of anemia in which the red blood cells rupture (known as hemolysis) and become dysfunctional. This could happen due to a variety of reasons. Some forms of hemolytic anemia can be hereditary with constant destruction and rapid reproduction of red blood cells. This destruction may also happen to normal red blood cells in certain conditions, for example, with abnormal heart valves damaging the blood cells.
* Other less common causes of anemia include medication side effects, thyroid problems, cancers, liver disease, other genetic disorders, lead poisoning, AIDS, and bleeding disorders. It is noteworthy that there are many other potential causes of anemia that are not included in this list and these are only some of the more common and important ones.
Symptoms of Anemia
Signs and symptoms vary depending on the cause of your anemia, but may include:
* Pale skin
* A fast or irregular heartbeat
* Shortness of breath
* Chest pain
* Cognitive problems
* Cold hands and feet
Initially, anemia can be so mild it goes unnoticed. But signs and symptoms increase as anemia worsens.
How Is Anemia Treated?
Treatment for anemia depends on the type, cause, and severity of the condition. Treatments may include dietary changes or supplements, medicines, or procedures.
Goals of Treatment
The goal of treatment is to increase the amount of oxygen that your blood can carry. This is done by raising the red blood cell count and/or hemoglobin level. (Hemoglobin is the iron-rich protein in red blood cells that carries oxygen to the body.)
Another goal is to treat the underlying condition or cause of the anemia.
Dietary Changes and Supplements
Low levels of vitamins or iron in the body can cause some types of anemia. These low levels may be due to poor diet or certain diseases or conditions.
To raise your vitamin or iron level, your doctor may ask you to change your diet or take vitamin or iron supplements. Common vitamin supplements are vitamin B12 and folic acid (folate). Vitamin C sometimes is given to help the body absorb iron.
Your body needs iron to make hemoglobin. Your body can more easily absorb iron from meats than from vegetables or other foods. To treat your anemia, your doctor may suggest eating more meat—especially red meat (such as beef or liver), as well as chicken, turkey, pork, fish, and shellfish.
Nonmeat foods that are good sources of iron include:
* Spinach and other dark green leafy vegetables
* Peas; lentils; white, red, and baked beans; soybeans; and chickpeas
* Dried fruits, such as prunes, raisins, and apricots
* Prune juice
* Iron-fortified cereals and breads
You can look at the Nutrition Facts label on packaged foods to find out how much iron the items contain. The amount is given as a percentage of the total amount of iron you need every day.
Iron also is available as a supplement. It’s usually combined with multivitamins and other minerals that help your body absorb iron.
Doctors may recommend iron supplements for premature infants and infants who are fed breast milk only or formula that isn’t fortified with iron.
Large amounts of iron can be harmful, so take iron supplements only as your doctor prescribes.
Low levels of vitamin B12 can lead to pernicious anemia. This type of anemia often is treated with vitamin B12 supplements.
Good food sources of vitamin B12 include:
* Breakfast cereals with added vitamin B12
* Meats such as beef, liver, poultry, and fish
* Eggs and dairy products (such as milk, yogurt, and cheese)
* Foods fortified with vitamin B12, such as soy-based beverages and vegetarian burgers
Folic acid (folate) is a form of vitamin B that’s found in foods. Your body needs folic acid to make and maintain new cells. Folic acid also is very important for pregnant women. It helps them avoid anemia and promotes healthy growth of the fetus.
Good sources of folic acid include:
* Bread, pasta, and rice with added folic acid
* Spinach and other dark green leafy vegetables
* Black-eyed peas and dried beans
* Beef liver
* Bananas, oranges, orange juice, and some other fruits and juices
Vitamin C helps the body absorb iron. Good sources of vitamin C are vegetables and fruits, especially citrus fruits. Citrus fruits include oranges, grapefruits, tangerines, and similar fruits. Fresh and frozen fruits, vegetables, and juices usually have more vitamin C than canned ones.
If you’re taking medicines, ask your doctor or pharmacist whether you can eat grapefruit or drink grapefruit juice. This fruit can affect the strength of a few medicines and how well they work.
Other fruits rich in vitamin C include kiwi fruit, strawberries, and cantaloupes.
Vegetables rich in vitamin C include broccoli, peppers, Brussels sprouts, tomatoes, cabbage, potatoes, and leafy green vegetables like turnip greens and spinach.
Your doctor may prescribe medicines to increase the number of red blood cells your body makes or to treat an underlying cause of anemia. Some of these medicines include:
* Antibiotics to treat infections.
* Hormones to treat heavy menstrual bleeding in teenaged and adult women.
* A man-made version of erythropoietin to stimulate your body to make more red blood cells. This hormone has some risks. You and your doctor will decide whether the benefits of this treatment outweigh the risks.
* Medicines to prevent the body’s immune system from destroying its own red blood cells.
* Chelation (ke-LAY-shun) therapy for lead poisoning. Chelation therapy is used mainly in children. This is because children who have iron-deficiency anemia are at increased risk of lead poisoning.
If your anemia is severe, you may need a medical procedure to treat it. Procedures include blood transfusions and blood and marrow stem cell transplants.
A blood transfusion is a safe, common procedure in which blood is given to you through an intravenous (IV) line in one of your blood vessels. Transfusions require careful matching of donated blood with the recipient’s blood.
For more information, go to the Diseases and Conditions Index Blood Transfusion article.
Blood and Marrow Stem Cell Transplant
A blood and marrow stem cell transplant replaces your faulty stem cells with healthy ones from another person (a donor). Stem cells are found in the bone marrow. They develop into red and white blood cells and platelets.
During the transplant, which is like a blood transfusion, you get donated stem cells through a tube placed in a vein in your chest. Once the stem cells are in your body, they travel to your bone marrow and begin making new blood cells.
For more information, go to the Diseases and Conditions Index Blood and Marrow Stem Cell Transplant article.
If you have serious or life-threatening bleeding that’s causing anemia, you may need surgery. For example, you may need surgery to control ongoing bleeding due to a stomach ulcer or colon cancer.
If your body is destroying red blood cells at a high rate, you may need to have your spleen removed. The spleen is an organ that removes wornout red blood cells from the body. An enlarged or diseased spleen may remove more red blood cells than normal, causing anemia.