Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis. The bacteria usually attack the lungs, but TB bacteria can attack any part of the body such as the kidney, spine, and brain. If not treated properly, TB disease can be fatal.
  
Not everyone infected with TB bacteria becomes sick. As a result, two TB-related conditions exist: latent TB infection and TB disease. Both latent TB infection and TB disease can be treated. Learn more about the difference between latent TB infection and TB disease.
  
     Treatment for Latent TB Infection
  
People with latent TB infection have TB bacteria in their bodies, but they are not sick because the bacteria are not active. People with latent TB infection do not have symptoms, and they cannot spread TB bacteria to others. However, if TB bacteria become active in the body and multiply, the person will go from having latent TB infection to being sick with TB disease. For this reason, people with latent TB infection are often prescribed treatment to prevent them from developing TB disease. Treatment of latent TB infection is essential for controlling and eliminating TB in the United States.
  
Because there are less bacteria in a person with latent TB infection, treatment is much easier. Four regimens are approved for the treatment of latent TB infection. The medications used to treat latent TB infection include:
  
   - isoniazid (INH)
   - rifampin (RIF)
   - rifapentine (RPT)
  
  
Certain groups of people (such as people with weakened immune systems) are at very high risk of developing TB disease once infected with TB bacteria. Every effort should be made to begin appropriate treatment and to ensure completion of the entire course of treatment for latent TB infection.
  
More: Treatment for Latent TB Infection
  
     Treatment for TB Disease
  
TB bacteria become active (multiplying in the body) if the immune system can't stop them from growing. When TB bacteria are active, this is called TB disease. TB disease will make a person sick. People with TB disease may spread the bacteria to people with whom they spend many hours.
  
TB disease can be treated by taking several drugs for 6 to 9 months. There are 10 drugs currently approved by the U.S. Food and Drug Administration (FDA) for treating TB. Of the approved drugs, the first-line anti-TB agents that form the core of treatment regimens include:
  
   - isoniazid (INH)
   - rifampin (RIF)
   - ethambutol (EMB)
   - pyrazinamide (PZA)
  
  
Regimens for treating TB disease have an initial phase of 2 months, followed by a choice of several options for the continuation phase of either 4 or 7 months (total of 6 to 9 months for treatment). Learn more about the continuation phase of treatment.
  
It is very important that people who have TB disease finish the medicine, taking the drugs exactly as prescribed. If they stop taking the drugs too soon, they can become sick again; if they do not take the drugs correctly, the TB bacteria that are still alive may become resistant to those drugs. TB that is resistant to drugs is harder and more expensive to treat.
  
More: Treatment for TB Disease
  
     Treatment Completion
  
Treatment completion is determined by the number of doses ingested over a given period of time. Although basic TB regimens are broadly applicable, there are modifications that should be made under special circumstances (such as people with HIV infection, drug resistance, pregnancy, or treatment of children).