Skip to content

Lung Disease & Respiratory Health Center

Font Size

Tuberculosis (TB) - Exams and Tests

Diagnosing active TB in the lungs

Doctors diagnose active tuberculosis (TB) in the lungs (pulmonary TB) by using a medical history and physical exam, and by checking your symptoms (such as an ongoing cough, fatigue, fever, or night sweats). Doctors will also look at the results of a:

Diagnosing latent TB in the lungs

  • A tuberculin skin testtuberculin skin test will show if you have ever had a TB infection. See a picture of a tuberculin skin test camera.gif.
  • Rapid blood tests help detect latent TB.3 They can help diagnose TB when results from a tuberculin skin test are uncertain. These tests also can tell if a person who has had a BCG vaccination has a TB infection. A rapid test requires only one visit to the doctor or clinic, instead of two visits as required for the tuberculin skin test. Rapid blood tests are also called interferon-gamma release assays (IGRAs).

Diagnosing TB outside the lungs

Diagnosing TB in other parts of the body (extrapulmonary TB) requires more testing. Tests include:

Testing for HIV infection is often done at the time of TB diagnosis. You may also have a blood test for hepatitis.

    1|2
    Next Article:

    Today on WebMD

    man coughing
    You may not even know you have it.
    blood clot
    Signs of this potentially fatal complication.
     
    man coughing
    When a cold becomes bronchitis.
    human lungs
    Causes behind painful breathing, fluid buildup.
     

    chest x-ray
    Slideshow
    Bronchitis Overview
    SLIDESHOW
     
    Copd Myth Fact Quiz
    QUIZ
    Energy Boosting Foods
    SLIDESHOW
     

    Pollen counts, treatment tips, and more.

    It's nothing to sneeze at.

    Loading ...

    Sending your email...

    This feature is temporarily unavailable. Please try again later.

    Thanks!

    Now check your email account on your mobile phone to download your new app.

    lungs
    Article
    smokestacks
    Article
     
    woman coughing
    Article
    Lung xray and caduceus
    Article
     

    WebMD Special Sections