IPhone Click Sound At The Top?

I have a iPhone 5s & I've had it for two years now. I'm 15 and i'm very picky about things especially my phone. I've noticed that the top right of my screen is popping up a little and makes a click sound everytime push down on it. Do anyone know how long I have before this becomes a major problem?

My brother had this problem a while ago, he dropped his phone and the corner of his phone popped up. It was fine for a while until the corner of the screen started going black. He left it for a while, but dropped it again and the the corner started coming off more. I'd get it fixed as soon as you can, just to make sure that the screen doesn't start going black, and because if you get it fixed while the damage is only minor, then it will cost less.