Page last reviewed: 13/07/2011

The term 'hangover' is used to describe the symptoms experienced after drinking a large amount of alcohol.

Symptoms include tiredness, headache and dehydration.

Most people get hangover symptoms after drinking large quantities of alcohol - even those who are not generally considered to be heavy drinkers.

It may be dangerous to drive or operate heavy machinery while hungover, even if your blood alcohol level is under the legal limit. The maximum blood alcohol level permitted by law when driving is 50mg per 100ml of blood, but it is safer to avoid alcohol completely if you intend to drive within the next 24 hours.

Hangovers have social as well as health costs. Employers lose thousands of work hours every year to staff who take sick days or whose work performance is affected due to hangovers. Heavy drinkers can show violent tendencies and personal relationships may suffer as a result.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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