This information sheet provides general information about TB is, how someone can be exposed and how to test for TB. It explains that TB is spread through the air after someone with TB disease sneezes, coughs, speaks, laughs, or sings. Latent TB infection is when TB germs live in the body without making the individual sick. If the germs become active, they cause TB disease. The two tests used to help detect TB are the skin test and a special TB blood test. Other tests include chest X-ray and sputum test.