Chosen Solution

I’m trying to diagnose the problem before I order parts. I have a 5th generation ipod touch. The screen has popped off on the left hand side of the case. I have tried pressing it back into place with no luck. I’ve tried pressing firmly as well- it move freely put nothing clicks into place. I’m trying to figure out if the issue is the adhesive has gone bad or if it is the plastic clip around the case?

The battery may be swelling. Swollen batteries can pop trackpads off Mac Laptops and make phone screens bulge like that. Here is how you can open up the iPod to check if the battery is swelling. iPod Touch 5th Generation Battery Replacement

It can also be a slightly bent case. The case can bend out of shape from pressure in pockets or being dropped. If that is the problem, it can often be fixed by being placed under weight (car battery, large water jug, etc.). You can also get a new frame. (Though I’d check on the battery first, as Aaron suggested.)