When you are getting a shot/injection, avoid stiffening the area. This can hurt you more. Instead relax the area and you won't feel much pain.

Normally when you are getting or about to get a shot, you tend to feel much tensed and this stiffens the area where you are getting the shot. Tightening your muscles or clutching your fist can make the shot hurt you more. Instead, relax your muscles and the shot will be less painful.