The immune system is the body's natural defense system that helps fight infections. An impaired immune system does not work properly and can't effectively protect a person against infection.
Some conditions and medicines weaken or impair the immune system. These may include:
- Alcohol or drug abuse or withdrawal.
- Certain diseases or conditions. Diabetes, cancer, HIV/AIDS, or conditions in which the body mistakenly identifies its own tissues as harmful (autoimmune disorders) are some examples.
- Chemotherapy or radiation therapy.
- Some medicines, such as corticosteroids or those taken to suppress the immune system after an organ transplant.
- Surgery to remove the spleen (splenectomy).
© Healthwise, Incorporated.