Bulging out of the screen of iPhone X

I have been using my iPhone X since April 2018. Everything of the phone is working perfectly. But surprisingly the screen has bulged out a bit from the body. Although the functioning of the phone is not hampered as yet. But this bulge is very awkward. Is there any problem with the battery ? But my battery is absolutely perfectly working and never betrays me during the entire day, once it’s charged fully at night. What do I do ? Please help.