Pain in bck of neck and sharp pain on my left arm below elbow and in left leg? wat could this be? could it be my mattress springs?

Pain is obscure: Could be the mattress springs. Unlikely neurologic in origin, more likely from musculoskeletal "improvisations ", irritating nerves outside the central nervous system. Check with a local osteopathic physician who specializes in neuromusculoskeletal pain. Try slow stretches- one leg gently over the other lying on your side - 3-5 minutes each side- arms out like an airplane.