Hello Sharon, and thanks for posting,

It may well be a pain syndrome, or related to surgical scar tissue pressing on some small nerve endings. Do speak further with your GP about it.

Sometimes, minor surgery is possible to release scar tissue but not always. You may benefit from a physiotherapy assessment. Try and do some very gentle slow stretching exercises for the chest wall and arms and shoulders (upper body). It may be that daily exercises to strengthen surrounding muscles may help.

Consider your sleeping position in bed. Using pillows to support you when on one side may help. Sometimes a TENS machine can help, but only under guidance from a health professional/physiotherapist.

I hope this helps, 

Best wishes,

Vanda