The common cure, at least here (in Sweden, that is), a pint of water before you go to bed (and who the hell remember that one?), and then again water, water, water, when you get up in the morning...(read: afternoon..

Working as a nurse in intensive care, i know how important minerals and salts are to our bodies, so here's my remedy:
Water IS important, but only like say 2 cups/half a liter every two hours, combined with bananas, tomatoes, cuecumbers, and all veggies and fruits found really, cause they contain what we contain on a cellular level.. that way you minimize headache, anxiety.. and all the shitty feelings.....