I went to the doctor to get my tb shot (required by the immunization form), and I was tested positive on the skin test. I went ahead and took an x-ray chest test to see if i had active tuberculosis, and I'm waiting on the results for that. Say worse comes to worse and I do have active tb, what would that spell out for my military career and appointment?
If you have active TB, you are in a pickle. But the chances that you do are very, very slim, and you would likely be symptomatic.
A postive PPD result means that, at some point, you've been exposed to TB. If left untreated, statistically you have about a 2% chance yearly of developing active TB. Once your chest x-ray confirms that you don't have active TB, you will likely start a cycle of a medicine called isonicotinylhydrazine (INH), probably as the brand name Isoniazid or Laniazid. The medicine effectively treats the mycobacteria that cause TB. There are hepatic (liver) side effects, but since you're too young to drink many of them will not be of particular concern to you. The full cycle of INH can last up to 9 months, IIRC, but is usually stopped after 6 to prevent hepatic side effect issues.
When my brother applied to USAFA, he had the same result. He started INH and they gave him his dose daily during BCT.
My wife is a physician and due to her work in an urban ER, she also had to go through an INH cycle before our wedding. It was inconvenient, but did not disrupt her life. She did a 6-month cycle.
Make sure it is well annotated in your records, as PPDs are a regular part of military life and you should be exempt from all future PPDs, as you will forever come up positive (the purified protein derivative tests for your body's reaction, which indicates exposure). Once your INH is complete, there's nothing more to do, so you can be exempted from further PPD testing.
Hopefully, kp2001 can pop in and offer you more info. And if I've said anything wrong, he can certainly correct me (most of this is from memory based on my wife's experiences as well as those of my brother, and my wife's knowledge). But, from what I have seen, it is by no means a show-stopper and you should not be overly worried.