The effects of a big night out could last longer than you think, a new study suggests.
The cognitive impairments seen when people are drunk are still present the day after, when there is little to no alcohol left in the bloodstream.
Psychologists at the University of Bath have discovered that hungover people have poorer attention, memory and psychomotor skills such as co-ordination and speed compared to when sober.
The researchers suggest their findings have important implications when it comes to activities performed when hungover, including driving.
For example, while hungover, individuals might typically wait until they believe there is no alcohol in the system before driving.
These new results suggest we could still be impaired in terms of the cognitive processes required, even after alcohol has left the bloodstream.
In addition, the researchers warn that although many workplaces have clear policies in place regarding alcohol intoxication at work, few cover the next-day effects of alcohol.
For certain jobs, they suggest, employees should be aware of the real effects that hangovers can have, and employers might do well to consider revising guidelines on safety grounds.
The hangover is the most commonly reported negative consequence of alcohol use and is estimated to cost billions a year due to absenteeism.
Despite this, up until this point little has been done to examine the effects of being hungover "on the job".
"In our review of 19 studies we found that hangover impaired psychomotor speed, short and long-term memory and sustained attention," lead author Craig Gunn said.
"Impaired performance in these abilities reflects poorer concentration and focus, decreased memory and reduced reaction times the day after an evening of heavy drinking.
"Our review also indicated limited and inconsistent research on alcohol hangover and the need for future studies in the field."
Dr Sally Adams, senior author, added: "Our findings demonstrate that hangover can have serious consequences for the performance of everyday activities such as driving and workplace skills such as concentration and memory."
The study, A Systematic Review Of The Effects Of Alcohol Hangover On Cognitive Performance, is published in the journal Addiction.
Australian Associated Press