Impaired Immune System

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).

Current as of: May 22, 2015

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Peter Shalit, MD, PhD - Internal Medicine