last week I had an unexplained pain in right arm - like it was bruised. Nothing had happened. Then, same pain moved to other arm, then two days later was my thigh. Then, that night I woke up at 2 a.m. to a feeling like my blood was boiling inside my body followed by an extreme cold feeling (whole body). Since then, I have been experiencing off/on muscle twitches/spasms - cold hands/feet, hot flashes, very tired. My Dr. took blood work and everything looks fine. I m freaking out b/c online looks like really bad things and I m looking to learn what benign explanations it can be. Came on a week ago. Having radiating pain in my back too. Not sleeping well.