I have intense shooting pain in left shoulder and shoulder blade that comes and goes w/ pain lifting arm and when moving neck.what could it be?

Pinched nerve: Shoulder and/or shoulder blade pain can be caused by an irriated shoulder or a pinched nerve in the neck. If turning your head in the direction of pain causes the pain to shoot to your shoulder and shoulder blade there is a good chance it's coming from your neck.

Radiculpathy: You may have this left shoulder pian because of a pinched nerve in your neck. It a called cervical radiculopathy. It can casue pain in your shoulder and neck as well.