How can I be sure that I have fubrimayalgia. I have pain in my upper shoulder &back &cramps with hot sensation. Does fibro. Causes throbing in diff. Parts?

See a doctor. See a doctor asap to get a diagnosis. You need an exam and maybe some test. Fibromyalgia usually causes pain everywhere, but especially bilateral upper back, chest, elbows, wrists, buttocks, hips and or knees.