What is a hangover?
Alcohol is one of those licit substances that has been widely consumed since the dawn of time. Although it has a reputation for making social gatherings more enjoyable, it is a major public health problem.
Acute alcohol intoxication, veisalgia, or more commonly known as "the hangover," defines these difficult after-evening moments. With various symptoms, this condition occurs in the hours following excessive alcohol consumption, during the elimination phase. It reflects the toxic effects of alcohol on the body, especially the liver and brain.
It can occur from a single drink and beyond. The most frequent symptoms are: a feeling of weakness, fatigue, difficulty concentrating, nausea, vomiting, stomach ache, gastric cramps, headaches, hypersensitivity to noise and light, a feeling of intense thirst, reduced alertness and memory.
The absorption of ethanol is an important first step, which takes place mainly in the small intestine. With the exception of bones and fats, it diffuses into all tissues homogeneously, following the movement of water, and crosses the foeto-placental barrier. The main detoxification route for ethanol is hepatic. It involves two stages of saturable oxidation that work to their full potential as soon as the blood alcohol level reaches 0.10 g/L: oxidation of ethanol to acetaldehyde by alcohol dehydrogenase, then acetaldehyde to acetic acid by acetaldehyde dehydrogenase. Many factors are likely to modify the absorption and/or metabolism of ethanol: genetic or drug-related, for example. Analytical methods for the detection of an alcoholic state of impregnation involve determination in the exhaled air or in the blood. In the context of road safety, measurements are carried out in the exhaled air with a legal limit of 0.25 mg/l of exhaled air.
Alcohol intoxication occurs when the threshold of 0.5 g/l of blood is exceeded, i.e. about 20 g of alcohol.
Lighter than water, its density of 0.79 makes it possible to calculate the quantity of ethanol contained in a drink. The alcoholic degree or centesimal alcoholic strength is the volumetric percentage of pure ethanol in a liquid mixture. For example, a standard 10 cl glass of wine measuring 12 alcoholic degrees contains 12 mL of pure ethanol, i.e. 12 × 0.8 (rounded to 0.79) = 9.6 grams of alcohol. Each glass or ''alcoholic unit'' therefore contains 10 grams of pure ethanol. Knowing that the detoxification metabolism is saturable and works at its maximum capacity as soon as the alcohol level reaches 0.10 g/L.