I've had an on-going case of minor to moderate oral thrush on the tongue. It's nowhere else in the mouth. Just the tongue. I read that most commonly, adults with thrush get it because they have a weakened immune system, with one obvious cause for that being HIV/AIDS. Now, I was last tested negative at the at the very least 21 weeks. Is it possible I do have a weakened immune system and maybe because of that, no HIV showed up on the test? Or is this being caused by something else? I will (shamefully) admit, for a while, I had gone with not-so-good oral hygiene, so maybe that's it? Of course I've also read a diet high in sugars can cause it as well. But once I read a common cause of thrush being a weak immune system, I couldn't help but think HIV and my test just wasn't accurate.