Sound Sleep, 'relief' or 'headache'?

Tweet

i am another person in the world who is very fond of sleep, or should rather say, that sleeping is my hobby. Given a peaceful room with a place to lie down, i can sleep till eternity. But last week i realized that sleeping for a long time,left me with a terrible headache which i could not get rid of till i took pills. We sleep sound when we are too much tired and that really helps to get us afresh the next morning. But i still wonder why did it happen that 10hrs of sleep gave me a terrible headache ? Can anybody tell me why? did you ever face such a problem?