Tuberculosis is an infectious disease caused by a bacterial germ called Mycobacterium tuberculosis . It is a very common infection.
Tuberculosis often affects the lungs, but it can also affect any part of the body.
It is a serious but treatable disease. Tuberculosis is spread when a person who has tuberculosis of the lungs coughs up bacteria that are then breathed in by other people. Healthy people, as well as people with weak immune systems, can develop tuberculosis after they breathe in the bacteria. A skin test is used to see if a person is infected with the tuberculosis germ. The skin test is called a PPD test or a tuberculin test.