A positive TB test simply indicates that you have been exposed to the bacteria that causes TB. There are a lot of people out there who have been exposed to it. 90% of the people exposed will never have problems with it. The TB bacteria has simply made its way into your body, generally into the lungs, but is just sitting there doing nothing and being kept in check by your immune system. This is known as Latent TB or TB infection. With TB infection, you have no signs of TB nor are you contagious to others. However, 5% exposed to TB can develop active TB or TB Disease within 1 year, and another 5% of people exposed will develop it sometime later in life, generally when they have conditions or diseases that affect their immune system. The good news is that you can take medication that will prevent a TB infection from becoming active.
The chest x-ray is indicated for people who have tested positive on their skin test. It simply indicates whether you have any damage in your lungs caused by TB; it cannot tell you if you have active TB, though. Once TB becomes active, it damages the lungs and these changes will always show up on a chest x-ray, even if you no longer have active TB.
The only way to positively tell if your TB infection has become active is to have a sputum test done. This is the next step you would go through IF your chest x-ray is positive. The good news is that TB is curable, but only by taking your daily medication.
The symptoms of active TB are a cough that lasts for more than 3 weeks, a bloody cough, weight loss, night sweats, fatigue, malaise. If you don't have any of these symptoms at present, it is doubtful that your positive skin test means anything more than you have been exposed to the TB bacteria. Once you have a positive skin test, you should never have another skin test done. Once you are positive, you will always test positive. If you were to have another skin test done, your immune system can "attack" the injection site and that in itself can cause serious problems.
Make sure you keep records of everything from your doctor and get copies of the chest x-ray report. You never know when you might need them. Good luck and don't worry! Even if you have active TB, it is curable! It just takes a little longer than we'd like!