Typical symptoms of a hangover may include headache, drowsiness, concentration problems, dry mouth, dizziness, fatigue, gastrointestinal distress (e.g., nausea, vomiting, diarrhea), absence of hunger, light sensitivity, depression, sweating, hyper-excitability, irritability, and anxiety.

[5] The socioeconomic consequences of hangovers include workplace absenteeism, impaired job performance, reduced productivity and poor academic achievement.

[7] An alcohol hangover is associated with a variety of symptoms that may include drowsiness, headache, concentration problems, dry mouth, dizziness, gastrointestinal complaints, fatigue, sweating, nausea, hyper-excitability, anxiety, and a feeling of general discomfort that may last more than 24 hours.

[3] Several pathophysiological changes may give rise to the alcohol hangover including increased levels of acetaldehyde, hormonal alterations of the cytokine pathways and decrease of the availability of glucose.

Additional associated phenomena are dehydration, metabolic acidosis, disturbed prostaglandin synthesis, increased cardiac output, vasodilation, sleep deprivation and insufficient eating.

[2] Some complex organic molecules found in alcoholic beverages known as congeners may play an important role in producing hangover effects because some, such as methanol, are metabolized to the notably toxic substances formaldehyde and formic acid.

[11] However, recent studies showed no significant correlation between hangover severity and the concentrations of various hormones, electrolytes, free fatty acids, triglycerides, lactate, ketone bodies, cortisol, and glucose in blood and urine samples.

In particular, in binge drinking the enzyme is activated and plays a role in creating a harmful condition known as oxidative stress which can lead to cell death.

For example, some people (predominantly East Asians) have a mutation in their alcohol dehydrogenase gene that makes this enzyme unusually fast at converting ethanol to acetaldehyde.

Congeners include substances such as amines, amides, acetones, acetaldehydes, polyphenols, methanol, histamines, fusel oil, esters, furfural, and tannins, many but not all of which are toxic.

[10] One study in mice indicates that fusel oil may have a mitigating effect on hangover symptoms,[20] while some whiskey congeners such as butanol protect the stomach against gastric mucosal damage in the rat.

Metabolism of methanol produces some extremely toxic compounds, such as formaldehyde and formic acid, which may play a role in the severity of hangover.

After a night of drinking, the resulting lack of key B and C vitamins, as well as potassium, magnesium, and zinc may cause fatigue, aching and other hangover-like symptoms.

Drinking water may help relieve symptoms as a result of dehydration but it is unlikely that rehydration significantly reduces the presence and severity of alcohol hangover.

[34] Health care professionals prefer to study alcohol abuse from a standpoint of treatment and prevention, and there is a view that the hangover provides a useful, natural and intrinsic disincentive to excessive drinking.

A four-page literature review in the British Medical Journal concludes: "No compelling evidence exists to suggest that any conventional or complementary intervention is effective for preventing or treating alcohol hangover.

The ancient Romans, on the authority of Pliny the Elder, favored raw owl's eggs or fried canary,[43] while the "prairie oyster" restorative, introduced at the 1878 Paris World Exposition, calls for raw egg yolk mixed with Worcestershire sauce, Tabasco sauce, salt and pepper.

[47] Other purported hangover cures include cocktails such as Bloody Mary or Black Velvet (consisting of equal parts champagne and stout).

[47] A 1957 survey by an American folklorist found widespread belief in the efficacy of heavy fried foods, tomato juice and sexual activity.

[22] The socioeconomic implications of an alcohol hangover include workplace absenteeism, impaired job performance, reduced productivity and poor academic achievement.

[68] In 2012, Éduc'alcool, a Quebec-based non-profit organization that aims to educate the public on the responsible use of alcohol, published a report noting hangovers have long-lasting effects that inhibit the drinker's capabilities a full 24 hours after heavy drinking.