Damage to the bone marrow's stem cells causes aplastic anemia. When stem cells are damaged, they don't grow into healthy blood cells.
The cause of the damage can be acquired or inherited. "Acquired" means you aren't born with the condition, but you develop it. "Inherited" means your parents passed the gene for the condition on to you.
Acquired aplastic anemia is more common, and sometimes it's only temporary. Inherited aplastic anemia is rare.
In many people who have aplastic anemia, the cause is unknown. Some research suggests that stem cell damage may occur because the body's immune system attacks its own cells by mistake.
Many diseases, conditions, and factors can cause aplastic anemia, including:
- Toxins, such as pesticides, arsenic, and benzene.
- Radiation and chemotherapy (treatments for cancer).
- Medicines, such as chloramphenicol (an antibiotic rarely used in the United States).
- Infectious diseases, such as hepatitis, Epstein-Barr virus, cytomegalovirus (si-to-MEG-ah-lo-VI-rus), parvovirus B19, and HIV.
- Autoimmune disorders, such as lupus and rheumatoid arthritis.
- Pregnancy. (Aplastic anemia that occurs during pregnancy often goes away after delivery.)
Sometimes, cancer from another part of the body can spread to the bone and cause aplastic anemia.
Certain inherited conditions can damage the stem cells and lead to aplastic anemia. Examples include Fanconi anemia, Shwachman-Diamond syndrome, dyskeratosis (DIS-ker-ah-TO-sis) congenita, and Diamond-Blackfan anemia.