Health Library

The Health Library is a collection of health and wellness resources created for learning and accessibility. Select a topic below for related health information or search for a topic in the search bar for more information on other medical conditions.

Spanish Translation

Top of the page

Mycobacterium avium complex

Mycobacterium avium complex (MAC) is a group of bacteria, commonly found in soil or water. People who have immune system problems can be infected with the bacteria. It can spread throughout the body and cause infection almost anywhere.

Symptoms include:

  • Night sweats.
  • Fever.
  • Diarrhea.
  • Fatigue.
  • Weight loss.
  • Belly pain.

There is no easy way to avoid exposure to Mycobacterium avium complex bacteria. But medicines are available that can prevent disease.

Current as of: May 1, 2026

Author: WebMD Ignite Staff

Clinical Review Board
All WebMD Ignite education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

This information does not replace the advice of a doctor. WebMD Ignite, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.