What is TB?

Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis. TB usually attacks the lungs, but can also affect other parts of the body such as the lymph nodes.

TB is spread when someone with infectious TB disease coughs, sending TB bacteria into the air. Another person can then breathe the bacteria into his/her lungs. This person's immune system may kill the TB germs. If the immune system doesn't kill the TB bacteria, the bacteria can remain alive but inactive in the body. This is called TB infection. A person with TB infection is not sick and cannot spread TB to others.

People with TB infection may progress to TB disease if their immune system weakens. A person with TB disease feels sick and may infect others. TB disease can be cured with antibiotics.

PDF Version

[Tuberculosis FACT SHEET - Index]