Types and causes
- Anemia of chronic disease: Certain chronic diseases (like cancer, rheumatoid arthritis and Crohn's disease) can interfere with the production of red blood cells, which may result in chronic anemia.
- Kidney failure may also cause anemia. The kidneys produce a hormone called erythropoietin, which stimulates the bone marrow to produce red blood cells. However, kidney failure or chemotherapy can cause a shortage of erythropoietin, which then results in a shortage of red blood cells.
- Aplastic anemia:
Aplastic anemia is life threatening. This condition occurs when the bone marrow is unable to produce enough of all three types of blood cells (red blood cells, white blood cells and platelets).
- The two main types of aplastic anemia are hereditary and acquired. Individuals are born with hereditary aplastic anemia, which is extremely rare. Acquired, which is the most common, is believed to be an autoimmune response that may be triggered by exposure to toxic chemicals, chemotherapy drugs, radiation or viral infections.
- Aplastic anemia is estimated to affect about 500-1,000 people in the United States each year. It is two to three times more common in Asian countries.
- Hemolytic anemia:
Several types of anemia are considered hemolytic. Hemolytic anemia develops when red blood cells are destroyed faster than the bone marrow can replace them. Common symptoms include jaundice (yellowing of the skin and eyes) and an enlarged spleen.
- Certain blood diseases can cause increased red blood cell destruction. Autoimmune disorders can cause the body to produce antibodies to destroy red blood cells. Certain medications and antibiotics that are used to treat infections (like penicillin, cephalosporins, levodopa, methyldopa and quinidine) may also cause red blood cells to decrease.
- Iron deficiency anemia: Iron deficiency anemia is the most common form of the disease. Researchers estimate that it affects about 20% of women, 50% of pregnant women and three percent of men in the United States. The World Health Organization considers iron deficiency to be the largest international nutritional disorder.
- Iron is necessary for the bone marrow to produce hemoglobin. If the body has inadequate levels of iron, there will not be enough hemoglobin for the red blood cells.
- There are two forms of dietary iron: heme and non-heme. Sources of heme iron include meat, fish and poultry. Sources of non-heme iron, which is not absorbed as well as heme iron, include beans, lentils, flours, cereals and grain products. Other sources of iron include dried fruit, peas, asparagus, leafy greens, strawberries and nuts. When red blood cells die, the body recycles the iron in them to produce new blood cells.
- Iron deficiency can occur if there is a significant amount of blood loss. One reason women are more susceptible to this form is that they menstruate each month. In addition, slow, chronic blood loss from a source within the body (like an ulcer or colon polyp) can lead to iron deficiency anemia. This condition can also occur if the diet is not rich in iron. In pregnant women, a growing fetus may deplete the mother's stored iron, causing her to develop iron deficiency anemia.
- Megaloblastic anemia:
When the body lacks vitamins that are needed to produce a sufficient amount of healthy red blood cells, the condition is known as megaloblastic anemia. The condition causes the red blood cells to be much larger than normal. In addition to iron, folate and vitamin B12, are needed to produce healthy red blood cells. Therefore, a diet lacking in either of these two nutrients can result in decreased red blood cell production.
- Individuals who have intestinal disorders that affect the absorption of nutrients are at risk for developing 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.
- Sickle cell anemia:
Sickle cell anemia is inherited and primarily effects African Americans and people of Arabic decent. Sickle cell anemia occurs in people who have a defective form of hemoglobin (hemoglobin S), which causes red blood cells to assume an abnormal crescent (sickle) shape. These irregular-shaped blood cells die early, causing a chronic shortage of red blood cells.
- Normal blood cells are flexible and round, and they are able to move freely through blood vessels in the body. However, the irregular-shaped blood cells in sickle cell anemia patients cannot travel through the body as easily. They often block blood flow through small blood vessels in the body and form blood clots.
- Sideroblastic anemia: Sideroblastic anemia is an enzyme disorder in which the body has sufficient amounts of iron, but it is unable to incorporate it into the hemoglobin. It is caused by the abnormal production of red blood cells as part of myelodysplastic syndrome, which can evolve into hematological malignancies (especially acute myelogenous leukemia).
- Other anemia:
There are several other, less common, forms of anemia, such as thalassemia and anemia caused by defective hemoglobin.
Copyright © 2011 Natural Standard (www.naturalstandard.com)
The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.