My phone is stuck.

I was using my phone when it suddenly froze. I pressed the home button to get out of the app I was using but nothing happened so I pressed the off button. But when I turn it back on, it was stuck to the lock screen with the wallpaper of my home screen. I pressed the home button multiple times and it did nothing but invert colours. I hold the off button and the red slide didn't appear. Please help me, I really can't get inside my phone.