alcohol dehydrates the body and brain cells..this is why one wakes up with a horrible "hang over"..
to avoid these shitty times I highly suggest drinking lots of water druing the drinking process..like a half gallon or more..and take a few aspirin before you pass out...it's not 100% full proof, but it can really help you avoid the pain the next day.
My other suggestion is the hair of the dog..
