Alcohol is converted in the body into acetaldehyde. This substance is responsible for, among others, hangovers. These chemical conversions take place in the liver.

Furthermore, the following changes take place when drinking alcohol (Alcohol level in per mille, 1/1000):

Alcohol level	For women	For men	Effect
0-0.5	About 1 glass	About 2 glasses	The blood vessels under the skin dilate, causing a warm feeling. Taste, smell and vision are reduced a little, and also the sense of pain is reduced.
0.5-1.5	About 1 to 5 glasses	About 2-7 glasses	There is a change of mood and behavior. There is overestimation. A numbing effect starts to play a role. Memory decreases, judging situations become more difficult, and speed of reaction is reduced. Muscle coordination is affected, vision changes.
1.5-3	About 5-9 glasses	About 7-14 glasses	All the above-mentioned effects are enhanced. Behavior becomes excessively emotional. Self-criticism disappear. The face becomes red and gets swollen, pupils dilate. The chance of nausea and vomiting is high.
3-4	9-13 glasses	14-19 glasses	The senses get numbed. The drinker is totally confused. He hardly notices what he hears and sees.
4			The risk of unconsciousness is very high. There is danger to life. He or she can go into a coma and possibly die of a heart attack or respiratory arrest.