What Causes Tuberculosis?

Diagnosing TB

There are various ways of diagnosing TB. First, the doctor does a medical exam and asks the patient about their symptoms. They listen to the patient’s lungs through a stethoscope and check for swelling in the lymph nodes. The doctor will then give the patient a chest X-ray, and take a sample of sputum if the X-ray suggests a problem. The doctor can also use a skin test to diagnose this condition, which involves an injection of PPD, or purified protein derivative tuberculin, just beneath the skin on the inside of the patient's forearm. The patient will experience swelling at the injection site for two to three days after the injection. The doctor can often tell through this swelling whether the person has been exposed to the tuberculosis bacteria. Blood tests are also another diagnostic tool that can determine if a patient has TB, and often tend to be more accurate than the tuberculosis skin test.