There are two kinds of enzymes in the human body that break down alcohol, one is ethanol dehydrogenase and the other is acetaldehyde dehydrogenase, both of which are mainly found in the liver in humans and in the livers of other animals. Alcohol is completely metabolized in human body after it is dehydrogenated into acetaldehyde by ethanol dehydrogenase and then decomposed into carbon dioxide and water by acetaldehyde dehydrogenase. There is a certain amount of ethanol dehydrogenase in the human body, while there are individual differences in the amount of acetaldehyde dehydrogenase in the human body. Under normal circumstances, some people are good at drinking alcohol, and some people are not good at drinking alcohol, which is related to the content of acetaldehyde dehydrogenase, some people have little content of acetaldehyde dehydrogenase or even defective, such people enter the body of alcohol, acetaldehyde can not be decomposed will produce a state of drunkenness, and in serious cases will produce coma.