If you're female, beware. You're more likely to be greeted with a pounding headache, stomachache and cotton-mouth the day after drinking than a male, even if you're the same height, size and weight. How can this be?
Men's bodies contain a higher percentage of water than women's bodies -- 55 to 65 percent for men, 45 to 55 percent for women -- which helps dilute any alcohol they consume [source: Cornell University]. Men also have more gastric alcohol dehydrogenase in their bodies, an enzyme that helps metabolize alcohol. This means men are able to break down booze when it's still in their stomach -- before it reaches their bloodstream and starts affecting their blood alcohol concentration, or BAC.
Another contributing factor? Women have a higher percentage of fat in their bodies. And fat can't absorb alcohol. Finally, female hormonal changes can affect their BAC. Studies show women will maintain their peak degree of intoxication longer than normal if they're taking oral contraceptives and during the week before they menstruate. All of these factors combined mean a woman will pretty much always become more intoxicated than a similarly sized man, even if she ingests a smaller amount of alcohol [sources: Cornell University, Hudepohl, WebMD].