Touch screen not working on iPod touch 4th gen.

I have an iPod touch 4th generation and I was using it less than 20 minutes ago. I tried using it about 5 minutes ago again and for some odd reason I can't unlock it. I can swipe the unlock bar but I can't type in my passcode, the only number that works is 0. I don't know why. I didn't get it wet, I didn't drop it. I carried it upstairs into my bedroom and tried to use it and for some reason its just not working! I have restarted it about 10 times now and still nothing has changed. If you can help that would be greatly appreciated, thank you!!