What happens to your body when you stay up all night?

Getting a consistent eight-hour sleep every night can seem near impossible. Whether you’re staying up late to cram as a student, having a big night with friends or binging a new series on Netflix, hitting the sack consistently by 10pm is hard to do. Even if you’re not a night owl, you might just find it hard to get to sleep. Excessive or late-night screen time, and poor lifestyle habits such as eating big meals before bed or having too much caffeine in the day, can also impact your quality and quantity of sleep. According to the Australian Sleep Health Foundation 33 to 45% of adults sleep poorly or not long enough and inadequate sleep can have a significant impact on our wellbeing.

Impaired reaction time, judgement and vision

When 17-year-old Randy Garner challenged himself to stay awake for 11 days back in the 1960s, after just one day he had trouble with his vision and lost basic coordination – by the end he was hallucinating. While extreme, this experiment highlights how sleep deprivation impacts you physically, including your sensory and motor functions. In fact, driving while sleep-deprived can be as dangerous as driving under the influence of alcohol, as your reaction time, judgement and vision are all impaired.

Dr Melissa Weinberg from Deakin University’s School of Psychology has studied the relationship between sleep and wellbeing. ‘The first function of sleep is to refuel your body. In the first few hours of deep sleep, your body is doing all the things it needs to do to re-energise,’ Dr Weinberg explains.

Poor information processing and memory

When you’re sufficiently charged during that first period of sleep, Dr Weinberg says you then move into the rapid eye movement (REM) sleep. ‘That’s where we dream. It’s the brain replenishing and refreshing. Even though we’re asleep, our brain is awake,’ she says.

According to Dr Weinberg it’s at this time that we learn and remember. ‘If you don’t sleep, your brain doesn’t have a chance to consolidate information,’ she cautions, which means if you’re pulling an all-nighter ahead of an exam, you’re probably wasting your time. ‘If you cram you risk losing it all,’ Dr Weinberg says and adds that overall we don’t perform with mental efficiency when tired.

Interestingly, research has revealed there is a direct link between sleep and memory – we need to sleep in order for our short-term memory to be converted into long-term memory.

Increased moodiness and decreased motivation

When you have not refuelled the brain and body with a good night’s sleep, there is a flow-on effect to how you feel. You may experience emotional instability and crabbiness, making you feel negative and unmotivated throughout the day. Sleep deprivation can also lead to irrational responses and aggressive behaviour. Dr Weinberg says a good night’s sleep can make a big difference to mood. Without sleep, you’re likely to be irritable and have trouble focusing. ‘You need to sleep to regulate your emotions and be functioning at your best,’ Dr Weinberg explains.

Listen to your body for better results

Staying up well past your bedtime can feel easy if you’re using stimulants like caffeine, but at some point, you’ll pay for it. ‘You need lower stimulation to regulate your body temperature. When it happens your brain will initiate the onset of sleep,’ Dr Weinberg explains. When you get this right, you’ll achieve a higher quality sleep.

Reducing stimulation also means allowing your brain to begin to switch off, so if you’re glued to your computer until the moment you fall into bed, you’ll increase the time it takes to reach restful sleep and hinder the quality of wakefulness you experience the next day.

Dr Weinberg suggests that we stop using screens for studying, working or entertainment at least 40 minutes before bed. If you must continue closer to bedtime, she suggests switching the backlighting on iPhone to a setting called night shift, or installing a light filtering phone app, such as Twilight. This reduces the amount of blue light that’s emitted, reducing the intensity of brain activity.

Better still, put your phone away and pick up a good old-fashioned book in print to let your brain relax into sleep and calmly prepare to absorb everything you’ve learned that day.