Lately in the last few days, the back part of the shoulderblade in my arm feels as if it is throbbing (like at the beat of a heart) repeatedly. Lately it's been increasing to happen more often and feels more tingly/throbbing at a faster rate. When this happens, I also sometimes feel a small pain in my chest or get a nauseating feel or headache. The same thing happens with one of my legs, except it goes all numb or weak, and puts me in deep pain. Can someone please tell me what is going on, and if so, how I can solve it?