Suggest Treatment For Severe Pain In The Shoulders

I have recently been for a check up at hospital as was experiencing pains in back near shoulder blades I was informed that its muscular pain and been given pain killers which have really helped. Yesterday I experienced muscular pain so took a pill. I washed my hands in really cold water and got a shooting pain up my back and shoulder blade for a couple of seconds.the water was really cold. Could this be anything to worry about ? I do worry myself silly at times.