hangover

physiological condition

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Last updated

July 23, 2026

Quick Summary

A hangover is a general feeling of unwellness that typically includes a headache and nausea, occurring after a period of heavy alcohol consumption. While the exact cause is not fully understood, several theories exist.1

One theory suggests dehydration, as alcohol is a diuretic that increases urination. Another proposes that the body's processing of alcohol depletes NAD+, a coenzyme vital for metabolic functions. Congeners, by-products of fermentation found in some alcoholic beverages, are also thought to contribute to hangovers due to their toxic nature.2

Currently, the most supported theory points to acetaldehyde, a chemical produced when the body metabolizes alcohol. Acetaldehyde is significantly more toxic than alcohol itself and may trigger the unpleasant symptoms of a hangover. The word "hangover" itself has been in use since the late 19th century, originally referring to something that survived or remained, later evolving to describe the effects of overconsumption.23

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alcoholism
Acute diseases
…of these syndromes is the hangover—a general malaise typically accompanied by headache and nausea. After a prolonged bout of drunkenness, however, severe withdrawal phenomena often supervene. These phenomena include tremulousness, loss of appetite, inability to retain food, sweating, restlessness, sleep disturbances, seizures, and abnormal changes in body chemistry (especially electrolyte…
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…of these syndromes is the hangover—a general malaise typically accompanied by headache and nausea. After a prolonged bout of drunkenness, however, severe withdrawal phenomena often supervene. These phenomena include tremulousness, loss of appetite, inability to retain food, sweating, restlessness, sleep disturbances, seizures, and abnormal changes in body chemistry (especially electrolyte…
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Why Does Drinking Give You a Hangover?
…their consumption, scientific research on hangovers is surprisingly limited. The current working theories offer only partial explanations or have been contradicted by research. So we don’t really know what causes hangovers, but we have some guesses. Let’s take a look at four popular theories that contribute to our hangover knowledge.
Read More
…their consumption, scientific research on hangovers is surprisingly limited. The current working theories offer only partial explanations or have been contradicted by research. So we don’t really know what causes hangovers, but we have some guesses. Let’s take a look at four popular theories that contribute to our hangover knowledge.
Read More