In what way high? Can you describe more of what you mean? Maybe something triggered it. :) Maybe you are having this from something really good happening. Or are you taking any new medication?
I get these "highs" but I get them during Hypomania, which is probably different from yours, and different reason, mine are almost euphoric at times. But I do know what you are talking about! :) Its hard to stop it when it starts. But for me if you find something to do creative or something you really enjoy to get yourself immersed in.
If it gets unbearable, then I suggest you get some help.