Tuberculosis (TB) is an infectious disease that usually infects the lungs, but can attack almost any part of the body. Tuberculosis is spread from person to person through the air. When a person with TB in their lungs or throat coughs, laughs, sneezes, sings, or even talks, the germs that cause TB may spread through the air. If another person breathes in these germs, there is a chance that they will become infected with tuberculosis.
It is not easy to become infected with tuberculosis. Usually a person has to be close to someone with TB disease for a long period of time. TB is usually spread between family members, close friends, and people who work or live together. TB is spread most easily in closed spaces over a long period of time.
If it is not treated, TB can be fatal. But TB can almost always be treated and cured if you take medicine as directed by your healthcare provider. Once you begin treatment, within weeks you will no longer be contagious. That means you can't spread the disease to others. If you take your medicine just as your healthcare provider tells you, all the TB germs should be killed.
What are the Symptoms of TB?
A person with TB infection will have no symptoms. A person with active TB disease may have any, all or none of the following symptoms:
- A persistent cough
- Constant fatigue
- Weight loss
- Loss of appetite
- Fever
- Coughing up blood
- Night sweats
These symptoms can also occur with other diseases so it is important to see a healthcare provider and to let them find out if you have TB. A person with TB disease may feel perfectly healthy or may only have a cough from time to time. If you think you have been exposed to TB, get a TB test.
How is TB Detected?
TB can be detected through a skin test or a TB blood test.
The skin test is done by injecting a small amount of fluid called tuberculin into the skin in the arm. You will be told to return within 48 to 72 hours to have a healthcare worker check the arm to see if a bump has developed. The healthcare worker will measure the bump and tell you if your reaction to the test is positive or negative. If it's positive, it usually means you have been infected with the TB germ.
The TB blood test measures how your immune system reacts to the germs that cause TB.
If you have a positive test for TB infection, it only means that you have been infected with TB germs. It does not tell whether you have developed TB disease. You will be given other tests, such as a chest x-ray and a check of your sputum (coughed up mucus), to see whether you have TB disease.