An illness in which TB bacteria are multiplying and attacking different parts of the body. The symptoms of active TB disease include cough, weakness, weight loss, fever, no appetite, chills, and sweating at night. A person with active TB disease may be infectious and spread TB to others.

A vaccine for TB. BCG is not widely used in the United States, but it is often given to infants and small children in other countries where TB is common.

A picture of the inside of your chest. A doctor can look at a chest x-ray to see whether TB bacteria have damaged your lungs.

A person who has spent time with a person with infectious TB.

A test to see whether there are TB bacteria in your phlegm or other body fluids.

A way of helping patients take their medicine for TB. If you get DOT, a health care worker meets with you every day or several times a week to make sure you are taking your medicine.

Active TB disease in any part of the body other than the lungs (for example, the kidney, spine, brain, or lymph nodes).

Infection with the human immunodeficiency virus (HIV), the virus that causes AIDS (acquired immunodeficiency syndrome). A person with both latent TB infection and HIV infection is at very high risk for active TB disease.

A medicine used to prevent active TB disease in people who have latent TB infection. INH is also one of the four medicines often used to treat active TB disease.

A condition in which TB bacteria are alive but inactive in the body. People with latent TB infection have no symptoms, don't feel sick, can't spread TB to others, and usually have a positive skin test reaction. But they may develop active TB disease if they do not receive treatment for latent TB infection.