Testing For Tuberculosis

How do you know if you have tuberculosis? If you or your health care provider think you may have tuberculosis, a medical evaluation can be set up which can involve physical examinations, TB tests, and chest X-rays.

The Physical examination will check for symptoms of TB which may include:

• fever
• unexplained weight loss
• fatigue
• chest pain
• coughing for 3 weeks or more
• coughing up blood

This examination will also look into other illnesses or infections that a patient may have which could affect the TB infection, such as HIV

There are two types of TB tests which can determine if you have the infection.

1. The Tuberculin skin test involves injecting a small amount of fluid into the arm of a patient. After 2 to 3 days, the patient's arm will be looked at to see if a reaction occurred. If the injected area is raised or swollen, this patient is likely to have TB.

   

   here, the health care provider measure the size of swelling/raising caused by the skin test fluid (cdc)

2. With a TB blood test, a patients blood is drawn and taken to a laboratory and presented with TB bacteria to measure the reaction of the person's immune system. If there is no reaction, it is likely that this patient does not have active or latent TB.

   

   cdc

Chest X-rays are used to look for abnormalities such as lesions that may appear with TB within the lungs. By themselves, these X-rays are not enough to determine if a person has TB, but they can help to rule out the possibility of a pulmonary TB infection. 

While difficult to spot with the untrained eye, this image demonstrates the ability to determine if a person has pulmonary TB through the use of x-rays.