IPhone Touch Screen Not Respondingby Pat Smith ; Updated September 28, 2017
One of the iPhone's selling points is its touch screen, called Multi-Touch display by Apple. Any lack of response from the touch screen can render your iPhone almost useless. You can address simple problems, such as frozen apps, at home before having to take or send the phone in for service. Touch screen unresponsiveness is one of the few phone problems for which Apple suggests taking the phone in for service versus a factory reset, as it's rarely a software problem.
Slow vs. Unresponsive
Your iPhone may just be slow, which is common when the iPhone is too full of data. Let your iPhone sit for a few minutes to see if it finishes processing any data and the speed improves. Force-quit the current program if necessary by holding down the sleep/wake button for a couple of seconds until the slider appears on the screen, and then release and hold down the home button for about two seconds. Once the program closes, test the home screen for responsiveness.
Apple suggests removing any protective film you have over your screen. Some third-party films are too thick and prevent the touch screen from reacting with enough sensitivity and speed. Alternately, if you don't have a protective film, clean your screen with a slightly damp and lint-free cloth to remove any oil or dirt buildup.
Restart and Reset
Restarting or resetting your phone will solve many software problems that are interfering with the screen. Hold down the sleep/wake button and slide the bar that appears on the screen to turn off the iPhone. Then hold down the sleep/wake button again for a couple of seconds until the phone turns back on. If regular restarting doesn't work, hold down the sleep/wake and home buttons simultaneously until the Apple logo shows up on the screen.
If no other options fix the touch screen problem, take your phone to an Apple store for service. Call the nearest Apple store if you're unable to go in and the representative will let you know your options. The touch screen failing is a hardware problem that, as long as you don't have water damage, is covered under the iPhone's warranty.