For the last five hours (no exaggeration) the upper left side of my back has been twitching nonstop. It twitches about every 8 seconds for no reason. Occasionally it will have a double or even a triple twitch. At first it was humorous, but now it is just annoying. I have taken a nap, expecting it to go away. But, when I work up it was still going on. Whats up with this?