I'm a barber so i use my hands frequently my right index fingertip is numb what can be causing this?

A tight watch: Is a possibility, repetitive motion of the wrist is another, the condition in both circumstances is carpal tunnel syndrome. While there may be other possible diagnosis's , carpal tunnel is certainly a main one.

Finger numbness: If you cut hair with your right hand, the scissors is compressing the sensory nerve in the finger. Try a different scissors or try to change your hand position to avoid compressing or rubbing the sides of the affected digit.