When your shoulder dislocates, it is not simply a matter of the ball-like humeral head popping out of the socket. A dislocation usually happens as a result of a sudden traumatic injury to the shoulder and arm. The movement of the humeral head coming out of its socket joint tears, separates, or stretches the surrounding ligaments, cartilage, and muscles. The intense pain you feel is an indication of how significant the damage can be.
This is not an injury you can nurse at home. In most cases, you will want to go to an emergency room, where medical professionals will attempt to put the humeral head back in place, and fortunately, they are successful most of the time. However, if they are unable to do that, you may need to be sedated either in the emergency department or the operating room so that you and your muscles completely relax, allowing the movement of the humeral head back into the socket.