According to WebMD, pulmonary tuberculosis is contagious. It spreads when a person with the disease breathes out, allowing the bacteria to pass to another person when he breathes it in. However, if TB develops in another part of the body, it is much less likely to spread to another person.
According to WebMD, certain people are at a greater risk of catching TB than others. This includes people who come into close contact with someone with TB, those who have the HIV virus, people with poor or little access to health care and those who abuse drugs or alcohol. When most people first catch the disease, the symptoms are so mild they may not even know they have it.
This is what is called "latent TB" and occurs when the body is able to keep the disease from becoming active, notes WebMD. Symptoms of an active TB infection include a cough that produces thick, cloudy or bloody mucus, night sweats, fever, tiredness, weakness, rapid heartbeat and shortness of breath. Treatment usually involves taking more than one medicine for a long period of time to prevent drug-resistant TB. Mayo Clinic states that a person who takes medicine regularly usually stops being contagious after two weeks.