It's a very common problem, Lenovo replaces them under warranty, but otherwise you'd need to buy and replace the hinges. They aren't expensive (about $15usd), but they aren't fun to install. When you install, be very careful when dissembling the Lid assembly, the bezel is glued on with double sided tape and also has clips, it's very easy to break the clips, and the screen is extremely easy to crack too. The right hinge is much easier then the left. Many people find that replacing only one does the job of making it feel tight again.