What is Tuberculosis (TST) Testing?

Tuberculosis screening and chest clinic follow-up if needed.

Questions and Answers About TB

Tuberculosis (TB) is a disease caused by a bacterium called Mycobacterium tuberculosis

Tuberculosis (TB) is a disease that is spread from person to person through the air. TB usually affects the lungs. The bacteria are put into the air when a person with TB of the lung coughs, sneezes, laughs, or sings. TB can also affect other parts of the body, such as the brain, the kidney, or the spine. Tuberculosis is a disease that can be cured if treated properly.

TB can affect anyone of any age

Anyone can get TB, but some people are at higher risk. Those at higher risk include:

  • Infants and small children
  • People who share the same breathing space (such as family members, friends, coworkers) with someone who has TB disease
  • People with low income who live in crowded conditions, have poor nutrition, and have poor health care
  • Homeless people
  • People born in countries where a lot of people have TB
  • Nursing home residents
  • Prisoners
  • Alcoholics and injection drug users
  • People with medical conditions such as diabetes, kidney failure, and those with weakened immune systems (such as HIV or AIDS)

The symptoms of TB disease may include:

Feeling weak or sick, rapid weight loss (over a few weeks or months), fever, or night sweats. Symptoms of TB of the lungs may include cough, chest pain, or coughing up blood. Other symptoms depend on the particular part of the body that is affected.

TB infection is different than TB disease

People with TB disease are sick from bacteria that are active in their body. They usually have one or more of the symptoms of TB. These people are often capable of giving the infection to others. Medications can cure TB disease; usually three or more medications are given to treat TB disease. People with TB infection (without disease) have the bacteria that cause TB in their body. They are not sick because the germ lies inactive in the body. They cannot spread the germ to others. Medications are often prescribed for these people to prevent them from developing TB disease in the future.

A skin test can tell if you have TB infection

You can get a TB skin test from a doctor or local health department. A negative test usually means the person is not infected. However, the test may be falsely negative in a person who has been recently infected (it usually takes 2 to 10 weeks after exposure to a person with TB disease for the skin test to be positive). The test may also be falsely negative if the person’s immune system is not working properly.

A positive skin test reaction usually means that the person has been infected with TB. It does not necessarily mean that the person has TB disease. Other tests, such as an x-ray or sputum sample, are needed to see if the person has TB disease.

If you have TB infection or disease:

  • Get all the tests required by your doctor.
  • Stay at home until your doctor tells you it is okay to return to work or school. Do not have visitors (especially children) until your doctor says it is okay.
  • Keep all your medical appointments.
  • Take all your TB medications as prescribed. In Maryland, the local health department works with doctors to treat almost all people with TB disease. The local health department will provide the correct antibiotics and make sure they are taken correctly. Medications must be taken for long periods of time (6 months or more).

Where do I call with questions about Tuberculosis screening and Chest Clinic?


MD Department of Health & Mental Hygiene – Epidemiology & Disease Control Program
Adapted from Centers for Disease Control “Tuberculosis-Get the Facts!