You neck a glass of prosecco in the departures lounge before sipping a bevvy or two when the trolly passes by – you’re on holiday, after all, and you’ve got to make the most of it.
But before you know it, you’re flirting with the cabin crew, dribbling in your sleep and giving absurd compliments to your fellow passenger. And don’t get us started on the mid-flight hangover.
Drinking alcohol before or during a flight has the undeniable ability to get us more pissed than a bunch of 18 years olds on their first night out. But what’s going on?
Dr Clare Morrison, from online doctor MedExpress, explained that we sometimes feel more drunk on a plane than on land, despite consuming the same volume of alcohol – and it’s all to do with air pressure.
“When on a plane, the barometric pressure in the cabin of a plane is lower than it normally is. This decreased pressure means that the body finds it harder to absorb oxygen - this can produce light-headedness or hypoxia [deficiency in the amount of oxygen reaching the tissues],” she previously told HuffPost UK.
“In other words, the lower level of oxygen in your blood means that you may seem more drunk in the air than you would on the ground after consuming the same amount of alcohol.”
Knocking yourself out with a double G&T might seem like a good way to pass a long-haul, but Professor Paul Wallace, whose research focuses on alcohol consumption, said you won’t have a particularly restful sleep. That’s because drinking alcohol before bed (or a snooze on the plane) can lead to a person missing out on the first stage of sleep - known as REM sleep.
″[You’re] ultimately heading straight into a deep sleep, meaning you’re most likely to wake up just a few hours later,” he told HuffPost UK. “In the course of one night you’re typically meant to have around six to seven cycles of REM sleep in order to wake up feeling refreshed and rejuvenated.
“However, when you drink alcohol you can only expect to achieve one to two cycles of REM sleep. This can inevitably effect the overall quality of your sleep, leaving you feeling less productive and exhausted the next day.”
Of course, drinking alcohol on a flight can have more consequences than a hangover – more than 400 airline passengers have been arrested on suspicion of being drunk in the past two years, an investigation in September found. And airlines have a right to refuse to carry passengers that they consider to be a potential risk to the safety of the aircraft, its crew or its passengers. “Disruptive passenger behaviour is one of the main reasons for aircraft diversions,” says the Civil Aviation Authority.
Airlines will decide on a case-by-case basis how drunk is too drunk, so drink that Bloody Mary with caution.
This article originally appeared on HuffPost.