Sleep during exam time - why it's important

Sleep during exam time – why it’s important

sleep during exam time

Sleeping for success

Make sure your teens avoid ‘cramnesia’ by ensuring they get enough sleep during exam time.

Teens are notoriously sleep-deprived, which you probably know if you’ve ever had to try and get one out of bed and into school on time. The complaining and protesting isn’t just an obnoxious ‘teenage thing’ though – teens actually experience a biological shift to a later sleep-wake cycle during adolescence. The release of melatonin (sleep-promoting hormone) occurs later in the evening than it does for children and adults, and drops later in the morning, meaning teens find it difficult to fall asleep early, and difficult to wake early. When the stress and pressure of exams is added to the mix, problems with the sleep cycle can intensify, causing a host of problems for the developing teenage brain.


Sleep deprivation and studying

The pressure to achieve during exam time means a lot of teens will study excessively, staying up late to try and make as much information as possible stick. The reality of those exams being just around the corner often lights a fire that can be surprising to parents, who are just happy to see their kids putting in the work. But these ‘cramming’ sessions could actually be jeopardising their academic success.

Volumes of research suggest lack of adequate sleep has a significant impact on learning and memory. While deprived of regular sleep, overworked neurons in the brain can’t function properly, which makes it harder to access information
learned previously. It also becomes more difficult to stay focused, which means the brain can’t properly receive information. Not getting enough sleep affects the ability to make sound decisions and alters a person’s mood – both of which also negatively affect learning and memory.

Staying awake for too long causes levels of the hormone cortisol to rise, which induces stress and anxiety. As cortisol levels rise from lack of sleep, levels of immunity-boosting T-cells fall, making the body far more susceptible to illnesses like colds and flu – and it can be much harder for teens to do their best when they’re feeling stressed and sick.

Sleep and the developing brain

During adolescence the brain undergoes dramatic developments, which are essential for the formation of a healthy adult brain later on. The pre-frontal cortex, which is the area of the brain responsible for complex thinking and decision-making as well as emotional regulation, goes through significant maturation during teenage years. This part of the brain is especially sensitive to the effects of sleep deprivation.

During sleep the brain actively consolidates memories, processes emotions, refreshes cells and clears out waste materials that could slow or damage proper functioning. Sleep is particularly critical for teens, as lack of sleep can increase the likelihood of a variety of social, emotional and behavioural risks, and have a notable negative impact on academic performance. Lack of sleep in teens can result in several problems:


  • Difficulties with memory
  • Trouble focusing
  • Reduced problem-solving ability
  • Poor decision-making and judgement


  • Generally lower marks
  • Poor-quality work
  • More frequent absence and tardiness

Social and behavioural

  • Higher likelihood of engaging in risky behaviours (smoking, drinking, drug use)
  • Aggression, and potentially, violence
  • Social withdrawal and difficulty connecting with others


  • Difficulty controlling emotions
  • More negative and irritable moods
  • Higher risk of anxiety and depression


Did you know? Lack of sleep has a similar effect to drunkenness. A study at the University of Poland revealed that staying awake for 20-25 hours is basically equivalent to having a blood alcohol level of 0.10%, which is over the legal driving limit in South Africa. Effects include blurred vision, slowed reflexes and numbness.

Brain power

To produce energy in the parts of the body that need it, cells are equipped with a chemical compound called adenosine triphosphate (ATP), which our bodies create while we sleep. A proper night’s sleep means enough ATP to power the brain optimally – it has extremely high energy requirements. Research has shown that those who sleep after studying are more likely to remember information than those who studied and stayed awake. They can also learn faster and more efficiently than those who stayed awake for long periods of time.


The hippocampus is the part of the brain that forms new memories based on experiences you’ve had. It replays
information gathered throughout the day, transferring the events to the long-term memory. Simply put, if you don’t sleep, you won’t form memories. Staying up late to ‘cram’ can therefore result in a kind of amnesia, as the brain hasn’t been able to process the information into memory.



Nolwazi Dhlamini

About Caitlin Geng

Your Family’s Content Editor, and a real word nerd who loves reading and writing. She was recently married, in 2018, and is a ‘mom’ to two loveable pugs. Caitlin received 3rd place in the ‘Galliova Up and Coming Food/Health Writer of the Year’ category in 2019!


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