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. Not everyone infected with TB bacteria becomes sick. As a result, two TB-related conditions exist: latent TB infection (LTBI) and TB disease. If not treated properly, TB disease can be fatal.
TB bacteria spread through the air from one person to another. When a person with TB disease of the lungs or throat coughs, speaks or sings, TB bacteria can get into the air. People nearby may breathe in these bacteria and become infected.
TB is NOT spread by:
- shaking someone’s hand
- sharing food or drink
- touching bed linens or toilet seats
- sharing toothbrushes
When a person breathes in TB bacteria, the bacteria can get into the lungs and begin to grow. From there, TB bacteria can move through the blood to other parts of the body, such as the spine and brain. TB disease in the lungs or throat can be infectious and the bacteria can spread to other people. TB in other parts of the body, like the kidneys or spine, is usually not infectious.
Signs and symptoms of TB disease depend on where in the body the TB bacteria are growing. TB bacteria usually grow in the lungs (pulmonary TB). TB disease in the lungs may cause symptoms such as:
- a bad cough that lasts 3 weeks or longer
- pain in the chest
- coughing up blood
- weakness or fatigue
- weight loss
- no appetite
- sweating at night