For those celebrating St. Patrick's Day with green beer, moderation is key, as alcohol has several negative effects on your body - many of which usually amount to a miserable morning-after.
Produced by the American Chemical Society (ACS) Office of Public Affairs, The Chemistry of Alcohol and Hangovers video explains the science behind these unpleasant after-effects that excessive drinking can have on the body.
They include headaches, caused by low blood sugar and allergic reactions to certain ingredients in liquor.
Nausea and upset stomach, resulting from alcohol's irritant effect, which stimulates the secretion of acid in the stomach.
Thirst, the result of alcohol's dehydrating effects on the body.