Just in time for your post New Year's suffering, here's a new breakdown of what really causes a hangover, which drinks are most likely to cause a bad one, and what you can and can't do to prevent it or cure it.
...Red wine and dark liquors like whiskey, brandy, bourbon and tequila produce more impurities, called congeners, during fermentation than lighter colored alcohol like wine, rum and vodka. Here's a handy congener chart. Congeners basically make all hangover symptoms worse. You maybe have noticed that although it's clear, bubbly gives a nasty headache. That's because carbonation increases your blood's absorption of alcohol...
...Also, that drinking buddy who's always warning you: Bro, don't mix? He is correct. Mixing various types of alcohol on a single night is unwise if your functioning potential the following day is important. Each alcohol produces different types of congeners which combine to create a strong cocktail of morning-after pain...