Hangovers don't just induce nausea, a thumping headache and a dry mouth, they make you stupid too, according to new research.
Experts have discovered that the hangover - technically the symptoms left behind after alcohol levels in the blood return to zero - impairs brain function.
Their findings suggest that a big night out can last far longer than the time it takes to regain sobriety and can affect what experts refer to as the brain's "working memory".
"The symptoms of an alcohol hangover are not just physiological - they affect cognitive functioning and mood as well which may lead to numerous undesirable life consequences," Dr Lauren Owen, Marie Curie postdoctoral research fellow at Keele University's school of psychology told The Telegraph.
"Although numerous scientific papers cover the acute effects of alcohol consumption, researchers have largely neglected the issue of alcohol hangover."
The hangover is still not fully understood and while it is thought to be partly a symptom of dehydration, chemicals in the drink are also thought to play a role.
The main form of alcohol found in drinks is ethanol, which the body breaks down into a chemical called acetate so it can be expelled from the body.
However, it can briefly form a toxic molecule called acetaldehyde. Low levels of methanol that can also be found in some alcoholic drinks and when this is broken down it forms more toxic compounds.
Complex organic molecules known as congeners can also be found in darker alcoholic drinks and are also thought to worsen a hangover.
It may go some way to explaining why drinking whisky can cause more of a hangover than drinking vodka.
Dr Owen's findings are preliminary, but so far she has observed that tasks that rely on what psychologists call "working memory" seem to be most affected.
Dr Owen said that the early results seem to indicate a five to ten per cent drop in performance of working memory and an increase in errors by around 30 per cent while participants were hungover.
Reaction times were also slower in those who were hungover and represented someone in their 20s as having the reaction times of someone in their 40s.
The results will be presented at a conference at Keele University where new evidence from the Netherlands about how a hangover induced by alcohol can also have an affect on driving performance.
Researchers have also been examining whether alcohol induced hangovers decline in with age.
Dr Richard Stephens, a senior psychology lecturer at Keele University who has organised the conference, said: "People tend to think that hangovers get worse with age, but we are finding that people generally suffer fewer hangovers."
He said that this is probably because older people learn what they can drink and what they can
- DAILY MAIL