TB testing is done through a skin test that will show if you have been infected with TB. The skin test cannot tell when you were infected with TB or if you have Active or Latent TB. If the skin test is positive for TB bacteria, the doctor will more order tests to see if you Active TB. 

Your doctor might order a: 

• Chest x-ray, to see if there is any damage to your lungs. 
• Sputum test, to see if the mucous that comes from your cough has TB bacteria