[amanda panda]

A sharp,shooting,numbing pain in arm pit going to the center chest and back down the right arm what should I do

[joypulv]

Pain of this sort can be many things. A doctor might start with the most common exams, feeling your armpit for swollen lymph nodes, and having you raise and rotate your arm and turn your neck to see about pinched nerves. A woman might want a mammogram if she hasn't had one.
Make an appointment and meanwhile soak in the tub for an hour, or use a heating pad with a damp washcloth between you and the pad, and gently move your arm to see if it still hurts after applying heat. Take tylenol, or ibuprofin if you can tolerate that.
If the pain persists and tests don't reveal what it is, consider a good chiropractor.