Anemia Caused by Chronic Diseases
Chronic (long-term) illnesses can cause anemia. Often, anemia caused by chronic diseases goes undetected until a routine test such as a complete blood count (CBC) reveals abnormal results. Several follow-up tests may be used to determine the underlying cause. There are many chronic conditions and diseases that can result in anemia. Some examples of these include:
- Kidney disease—Red blood cells are produced by the bone marrow in response to a hormone called erythropoietin, made primarily by the kidneys. Chronic kidney disease can cause anemia resulting from too little production of this hormone; the anemia can be treated by giving erythropoietin injections.
- Inflammatory conditions—Whenever there are chronic diseases that stimulate the body’s inflammatory system, the ability of the bone marrow to respond to erythropoietin is decreased. For example, rheumatoid arthritis (a severe form of joint disease caused by the body attacking its own joints, termed an autoimmune disease) can cause anemia by this mechanism.
- Other diseases that can produce anemia in the same way as inflammatory conditions include chronic infections (such as with HIV or tuberculosis, TB), cancer, and cirrhosis.
A number of tests may be used as follow up to abnormal results of initial tests such as a CBC and blood smear to determine the underlying cause of chronic anemia. Some of these may include:
- Reticulocyte count
- Complete metabolic panel (CMP)
- Tests for inflammation such as CRP
- Tests for infections such as HIV and TB.
Treatment of anemia due to chronic conditions usually involves determining and/or resolving the underlying disease. Blood transfusions may be used to treat the condition in the short term.