Hangover

Hangover refers to a set of acute physical and cognitive symptoms that occur after a period of heavy alcohol consumption. Symptoms commonly include headache, thirst, fatigue, dizziness, nausea, muscle aches, sweating, mood changes, and sensitivity to light or sound. Cognitive effects can include impaired concentration and slowed reaction time. The onset typically coincides with the time when blood alcohol concentration returns toward zero, and the symptoms usually peak when alcohol is fully cleared from the body. Duration ranges from several hours to about a day, depending on the amount of alcohol, individual metabolism, and whether sleep was disrupted.

Hangovers are believed to result from a combination of factors: dehydration due to increased urine production, electrolyte imbalances, stomach irritation and acid production, low blood sugar, and an inflammatory response triggered by acetaldehyde, a toxic metabolite of ethanol. The amount of acetaldehyde exposure and the presence of congeners—chemical byproducts found in many alcoholic beverages—are associated with increased severity. Other factors that can worsen symptoms include poor sleep, recent sleep deprivation, and individual susceptibility.

Prevention and management: There is no proven cure. Relief strategies focus on rehydration with water or oral rehydration solutions, electrolyte replacement, rest, and, if appropriate, over-the-counter analgesics such as ibuprofen or aspirin; people should avoid acetaminophen due to potential liver harm when alcohol is still in the system. Avoiding further alcohol ("hair of the dog") is not recommended as a long-term solution. Moderation, pacing drinks, consuming food, and choosing beverages with lower congener content can reduce risk.

Prognosis: Hangovers generally resolve within 24 hours, though symptoms may persist longer in some individuals after very heavy drinking. Complications are rare, but severe dehydration, persistent vomiting, or signs of alcohol poisoning require medical attention.