What causes anemia? (top)

There are close to 100 causes of anemia, including serious illness, vitamin or iron deficiencies, blood loss, diseases, or side effects of medication but there are 3 main bodily mechanisms that produce anemia;

• excessive destruction of RBCs (red blood count)

• blood loss

• inadequate production of RBCs

What are some common types of anemia? (top)

Common types of anemia and their causes include:

• Iron deficiency anemia: This most common form of anemia affects about one in five women, half of pregnant women and 3 percent of men in the United States. The cause is a shortage of the element iron in your body. Your bone marrow needs iron to make hemoglobin. Without adequate iron, your body can't produce enough hemoglobin for red blood cells. The result is iron deficiency anemia. One way your body gets iron is when blood cells die — the iron in them is recycled and used to produce new blood cells. So, if you lose blood, you lose iron. Women with heavy periods who lose a lot of blood each month during menstruation are at risk of iron deficiency anemia. Slow, chronic blood loss from a source within the body — such as an ulcer, a colon polyp or even colon cancer — also can lead to iron loss and iron deficiency anemia. Your body also gets iron from the foods you eat. An iron-poor diet can lead to this anemia. In pregnant women, a growing fetus can deplete the mother's store of iron, leading to iron deficiency anemia.

• Vitamin deficiency anemia: In addition to iron, your body needs folate and vitamin B-12 to produce sufficient numbers of healthy red blood cells. A diet lacking in these and other key nutrients can cause decreased red blood cell production. People who have an intestinal disorder that affects the absorption of nutrients are prone to this type of anemia. Some people are unable to absorb vitamin B-12 for a variety of reasons and develop vitamin B-12 deficiency anemia, which is sometimes called pernicious anemia. Vitamin deficiency anemia’s fall into a group of anemias called megaloblastic anemias, in which the bone marrow produces large, abnormal red blood cells.

• Anemia of chronic disease: Certain chronic diseases — such as cancer, rheumatoid arthritis, Crohn's disease and other chronic inflammatory diseases — can interfere with the production of red blood cells, resulting in chronic anemia. Kidney failure also can be a cause of anemia. The kidneys produce a hormone called erythropoietin, which stimulates your bone marrow to produce red blood cells. A shortage of erythropoietin, which can result from kidney failure or be a side effect of chemotherapy, can result in a shortage of red blood cells.

• Aplastic anemia: This is a life-threatening anemia caused by a decrease in the bone marrow's ability to produce all three types of blood cells — red blood cells, white blood cells and platelets. Many times, the cause of aplastic anemia is unknown, but it's believed to often be an autoimmune disease. Some factors that can be responsible for this type of anemia include chemotherapy, radiation therapy, environmental toxins, pregnancy and lupus.

• Anemias associated with bone marrow disease: A variety of diseases, such as leukemia and myelodysplasia, can cause anemia by affecting blood production in the bone marrow. The effects of these types of cancer and cancer-like disorders vary from a mild alteration in blood production to a complete, life-threatening shutdown of the blood-making process. Myelodysplasia is a pre-leukemic condition that can cause anemia. Additionally, other cancers of the blood or bone marrow, such as multiple myeloma, myeloproliferative disorders or lymphoma, can cause anemia.

• Sickle cell anemia: This inherited and sometimes serious anemia, which affects mainly people of African and Arabic descent, is caused by a defective form of hemoglobin that forces red blood cells to assume an abnormal crescent (sickle) shape. These irregular-shaped red blood cells die prematurely, resulting in a chronic shortage of red blood cells. Sickle-shaped red blood cells can also block blood flow through small blood vessels in the body, producing other, often painful, symptoms.

• Other anemias: There are several other, rarer forms of anemia, such as thalassemia and anemias caused by defective hemoglobin.

What are the risk factors of anemia? (top)

Certain infections, blood diseases and autoimmune disorders, exposure to toxic chemicals, and the use of some medications can affect red blood cell production and lead to anemia. Other people at risk of anemia are people with diabetes, people who are dependent on alcohol (alcohol interferes with the absorption of folic acid) and people who adhere to a strict vegetarian diet, who may not get enough iron or vitamin B-12 in their diet.

Below are common risk factors of anemia;

• Poor diet: Anyone — young or old — whose diet is consistently low in iron and vitamins, especially folate, is at risk of anemia. Your body needs iron and vitamins to produce sufficient numbers of red blood cells. Some that adhere to a strict vegetarian diet, who may not get enough iron or vitamin B-12 in their diet is at risk of anemia.

• Intestinal disorders: Having an intestinal disorder that affects the absorption of nutrients in the small intestine — such as Crohn's disease or celiac disease — puts you at risk of anemia. Surgical removal of or surgery to the parts of the small intestine where nutrients are absorbed can lead to nutrient deficiencies and anemia.

• Menstruation: In general, women are at greater risk of iron deficiency anemia than are men. That's because women lose blood — and with it, iron — each month during menstruation.

• Pregnancy: Pregnant women are at an increased risk of iron deficiency anemia because their iron stores have to serve the increased blood volume of the mother as well as be a source of hemoglobin for the growing fetus.

• Chronic conditions: For example, if you have cancer, kidney or liver failure, or another chronic condition, you may be at risk of what's called anemia of chronic disease. These conditions can lead to a shortage of red blood cells. Slow, chronic blood loss from an ulcer or other source within the body can deplete your body's store of iron, leading to iron deficiency anemia.

• Family history: If your family has a history of an inherited anemia, you also may be at increased risk of the condition.

How is anemia diagnosed? (top)

In many cases, doctors don't diagnose anemia until they run blood tests as part of a routine physical examination. A complete blood count (CBC) may indicate that there are fewer red blood cells than normal. Other diagnostic tests may include:

• Blood smear examination: Blood is smeared on a glass slide for microscopic examination of RBCs, which can sometimes indicate the cause of the anemia.

• Iron tests: These include total serum iron and ferritin tests, which can help to determine whether anemia is due to iron deficiency.

• Hemoglobin electrophoresis: Used to identify various abnormal hemoglobins in the blood and to diagnose sickle cell anemia, the thalassemias, and other inherited forms of anemia.

• Bone marrow aspiration and biopsy: This test can help determine whether cell production is happening normally in the bone marrow. It's the only way to diagnose aplastic anemia definitively and is also used if a disease affecting the bone marrow (such as leukemia) is a suspected cause of the anemia.

• Reticulocyte count: A measure of young RBCs, this helps to determine if production of red blood cells is at normal levels.

How is anemia treated? (top)

Treatment for anemia depends on the cause:

• Iron deficiency anemia: This form of anemia is treated with iron supplements, which you may need to take for several months or longer. If the underlying cause of iron deficiency is loss of blood — other than from menstruation — the source of the bleeding must be located and stopped. This may involve surgery.

• Vitamin deficiency anemias: Pernicious anemia is treated with injections — often lifetime injections — of vitamin B-12. Folic acid deficiency anemia is treated with folic acid supplements.

• Anemia of chronic disease: There's no specific treatment for this type of anemia. Doctors focus on treating the underlying disease. Iron supplements and vitamins generally don't help this type of anemia. However, if symptoms become severe, a blood transfusion or injections of synthetic erythropoietin, a hormone normally produced by the kidneys, may help stimulate red blood cell production and ease fatigue.

• Aplastic anemia: Treatment for this serious anemia may include blood transfusions to boost levels of red blood cells. You may need a bone marrow transplant if your bone marrow is diseased and can't make healthy blood cells. You may need immune-suppressing medications to lessen your immune system's response and give the transplanted bone marrow a chance to start functioning again.

• Anemias associated with bone marrow disease: Treatment of these various diseases can range from simple medication to chemotherapy to bone marrow transplantation. Treatment of these types of anemia usually involves a consultation from a blood specialist (hematologist).

• Hemolytic anemias: Managing hemolytic anemias includes avoiding suspect medications, treating related infections and taking drugs that suppress your immune system, which may be attacking your red blood cells. Short courses of treatment with steroids or gamma globulin can help suppress your immune system's attack on your red blood cells. If the condition has caused an enlarged spleen, you may need to have your spleen removed. The spleen — a small organ below your rib cage on the left side — filters out and stores defective red blood cells. Certain hemolytic anemias can cause the spleen to become enlarged with damaged red blood cells.

• Sickle cell anemia: Treatment for this incurable anemia may include the administration of oxygen, pain-relieving drugs, and oral and intravenous fluids to reduce pain and prevent complications. Doctors also commonly use blood transfusions, folic acid supplements and antibiotics. A bone marrow transplant may be an effective treatment in some circumstances. A cancer drug called hydroxyurea (Droxia, Hydrea) also is used to treat sickle cell anemia in adults.