What is Jet Lag?

What is Jet Lag?

Posted in Sleep Science
read time
3 mins

Have you ever suffered from desynchronosis? Or jet lag as it's commonly known. If you have taken any long haul flights you will probably have suffered from some of its symptoms.

In this article, we're looking at the ins and outs of some of the pesky side effects of travel that can make many of us feel deprived of sleep.


Why do we get jet lag?


You don’t just disrupt your usual daily routine when you decide to travel across time zones; you actually unsettle your usual sleep, socialising and digestion patterns. All in all, it can impact your brain function too.

According to research from the University of Washington, jet lag impacts two different groups of neurons in the suprachiasmatic nucleus (SCN), underneath the hypothalamus at the base of the brain. One set deals with deep sleep and physical fatigue while the other controls rapid eye movement sleep. When you speed across time zones, the neurons controlling REM sleep can struggle to adjust. This leaves the two groups misaligned and your internal body clock off kilter.

Businessman trying to get to sleep on a bench in an airport terminal


Jet lag usually starts to hit when we travel across three time zones or more in quick succession. We’re particularly susceptible to its ill effects when we voyage west-to-east. This is because this means we have to try and sleep when we’d usually be waking up. Although it can often feel like a struggle, our bodies are more capable of battling to stay up on extraordinarily long days than they are going to sleep unusually early.


What are the symptoms of jet lag?


Most people associate jet lag with tiredness because when you’re delaying sleep or trying to get your head down at strange times, fatigue usually kicks in. However, there are actually a number of symptoms associated with desynchronosis that you may not have encountered yourself or connected with adapting to time differences.


View of Planet Earth, half in sunlight, half in darkness.


The change in hormones, lack of sleep and eating at strange times can lead to indigestion, loss of appetite, diarrhoea and even constipation. Then there are signs of feeling more generally unwell – headaches, muscle soreness, nausea, and clumsiness.

Jet lag can also impact your personality – you may feel anxious or irritable. Unfortunately, the older you are, the more impact crossing time zones seems to have as it takes longer for your circadian rhythm to adjust. This means that when you head off on holiday the kids tend to bounce back very quickly while grandparents can often feel sluggish for a few days.


Avoiding jet lag


Although there is no magical solution to the problems of jet lag, there are a few ways of reducing its impact. Your best bet is to adjust activities like sleeping and eating a few days before so they are more in line with your destination. Getting stuck into your new time zone with enthusiasm can go a long way towards lowering that horrible feeling of a holiday hangover!

Speaking of hangovers, while you’re on the plane, it’s advisable to stay clear of alcohol and caffeine, which can keep you awake. You could also try saving a snack to eat during the usual mealtime of your destination as this can help get your body in synch. If you have trouble sleeping in hot conditions, see our top 11 summer sleep tips here.

What was your worst ever jet lag experience? Do you have any tips for avoiding it completely?