Until you open it up, there's no way to know. Try calling the doctor and telling him "I've got a headache- - - -what's wrong with me?" He's going to tell you to come in for some diagnostic work. Do you have a brain tumor or a hangover? Our wild guesses aren't any more accurate than his would be.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!