Causes of anemia
Different types of anemia have different causes. They include:
Iron deficiency anemia. Too little iron in the body causes this most common type of anemia. Bone marrow needs iron to make hemoglobin. Without enough iron, the body can’t make enough hemoglobin for red blood cells.
Pregnant people can get this type of anemia if they don’t take iron supplements. Blood loss also can cause it. Blood loss might be from heavy menstrual bleeding, an ulcer, cancer or regular use of some pain relievers, especially aspirin.
Vitamin deficiency anemia. Besides iron, the body needs folate and vitamin B-12 to make enough healthy red blood cells. A diet that doesn’t have enough of these and other key nutrients can result in the body not making enough red blood cells.
Also, some people can’t absorb vitamin B-12. This can lead to vitamin deficiency anemia, also called pernicious anemia.
Anemia of inflammation. Diseases that cause ongoing inflammation can keep the body from making enough red blood cells. Examples are cancer, HIV/AIDS, rheumatoid arthritis, kidney disease and Crohn’s disease.
Aplastic anemia. This rare, life-threatening anemia occurs when the body doesn’t make enough new blood cells. Causes of aplastic anemia include infections, certain medicines, autoimmune diseases and being in contact with toxic chemicals.
Anemias linked to bone marrow disease. Diseases such as leukemia and myelofibrosis can affect how the bone marrow makes blood. The effects of these types of diseases range from mild to life-threatening.
Hemolytic anemias. This group of anemias is from red blood cells being destroyed faster than bone marrow can replace them. Certain blood diseases increase how fast red blood cells are destroyed. Some types of hemolytic anemia can be passed through families, which is called inherited.
Sickle cell anemia. This inherited and sometimes serious condition is a type of hemolytic anemia. An unusual hemoglobin forces red blood cells into an unusual crescent shape, called a sickle. These irregular blood cells die too soon. That causes an ongoing shortage of red blood cells.