My hands get numb and feel funny each time i use my iphone what is this?

Nerve compression: When hands become numb with certain activities or during sleep this can be a sign of a nerve compression syndrome like carpal tunnel syndrome or cubital tunnel syndrome depending on which fingers are affected.

Pinched nerve: Which fingers are numb? Could be do to cubital tunnel syndrome (pinched nerve at elbow) if your ring and small finger go numb. If it is your thumb, index, and middle, could be carpal tunnel. If it is the ring and small, you are probably keeping your elbow bent too long.