Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. Possible causes of anemia include:
- Long-term (chronic) diseases such as chronic kidney disease, cancer, ulcerative colitis, or rheumatoid arthritis
- Destruction of red blood cells earlier than normal (which may be caused by immune system problems)
- Certain medications
- Some forms of anemia, such as thalassemia or sickle cell anemia, which can be inherited
- Pregnancy
- Problems with bone marrow such as lymphoma, leukemia, myelodysplasia, multiple myeloma, or aplastic anemia.
Source: NIH.gov