How poor sleep can affect your stress levels

Why bad nights happen to good people – and how to break the cycle

We’ve all been there. Lying awake at night, tossing and turning. With every tick of the clock, the problems seem to magnify and our stress levels soar.

And unfortunately, it works both ways. Yes, stress gets in the way of sleep, but lack of sleep can also exacerbate stress.

Why stress keeps us awake

Sleep might seem like the perfect antidote to a stressful day, but the brain receives a very different message.

Stress triggers the release of cortisol and adrenaline – powerful hormones that affect everything from your heart rate to your blood sugar levels, putting the body in a state of high alert.¹ 

This so-called ‘fight or flight’ response is helpful when we need to fight off a tiger – but not so useful when what we really need is a restful night, especially as the stress response remains heightened.² 

Indeed, a 2001 study by sleep scientists at Pennsylvania State University reported that insomniacs had raised levels of cortisol in their blood, particularly in the evenings, making it more difficult to fall and stay asleep.³

How sleep deprivation makes us feel stressed

A 1997 study published in Sleep found that people who were limited to just 4.5 hours of sleep a night for one week reported feeling stressed, angry, sad, and mentally exhausted.

The participants’ mood improved dramatically after two full nights of catch-up sleep.⁴ 

According to the National Sleep Foundation, people suffering from insomnia are 17 times more likely to suffer anxiety disorder, and 10 times more likely to develop depression.⁵

Lack of sleep = poorer coping strategies

Unfortunately, reduced sleep – and the associated stress – seriously affects our ability to cope with everyday life.

In a 2012 study published in the journal Emotion, healthy adults who had been sleep-deprived for one night felt stress, anxiety and anger more acutely in response to mild stressors.⁶ 

A different study, published in Psychosomatic Medicine in 2003, found that a lack of sleep may actually make problems seem more stressful.

A group of nearly 50 people – divided into insomniacs and good sleepers – were asked to write diaries recording their daily ups and downs, as well as sleep patterns.

Researchers found that both groups encountered similarly stressful events – but that the insomniacs perceived life to be more stressful.⁷

How to minimise the effects of reduced sleep

Sometimes, we can’t help but sleep less than our bodies need, for example, when caring for a newborn baby or working night or evening shifts.

But to reduce the effects of a sleep shortage on your brain, it’s still important to catch up on your zzzs where you can:

Power nap occasionally

Napping can help chip away at your sleep debt, which is the overall total of sleep you’ve missed. But be careful as naps can also throw your main sleep schedule out of sync.⁸

Snooze longer at the weekend

If you’ve missed hours of sleep during the week, it’s fine to allow yourself a few extra hours at the weekend.⁹

Turn off the alarm clock

When you’re on holiday or don’t have to get up for work, allow yourself to sleep as long as your body needs by waking up naturally, without an alarm clock.¹⁰ 

In the meantime, reminding yourself you’re sleep-deprived should help keep things in perspective.

Last updated: 3 June 2021