24 May 2022

What is Sleep and Why is it Important?

Sleep is as essential to our physical and emotional health. After all, it’s how an average person spends over a third of their lifetime! Read more about how you can improve your relationship with sleep and why it’s important to do so here. 

What is sleep and why is it important?

Sleep is as essential to our physical and emotional health as air, food and water, with the average person spending 36% of their lifetime asleep. 

Normal sleep consists of four stages and each of these stages is equally important. During sleep, the brain continues to work hard; memories are processed; learning is consolidated; waste is removed, detoxifying the brain of harmful proteins; and hormones are released to aid tissue growth and repair. 

Our circadian rhythm (internal body clock) follows a 24-hour cycle and uses information from our environment, such as lighting levels, to tell the body and brain when to perform certain functions, including falling asleep and waking up. 
When not disrupted, our circadian rhythm promotes a consistent and restorative sleep/ wake cycle. However, if disturbed, it can create sleeping problems, e.g. when we are jet lagged.

Potential impacts of lack of sleep 

Insufficient sleep can adversely affect both our physical and emotional wellbeing. As well as the perhaps expected impact of fatigue and lethargy, a lack of sleep can lead to overeating, as the regulation of hormones is disrupted, as such, the chosen foods tend to offer high energy value but very little in the form of nutritional quality.
We may also be more susceptible to minor illnesses such as the common cold, as sleep is understood to affect our white blood cells and therefore the function of our immune system. 

Poor sleep increases the risk of certain health conditions. For example, it is understood to increase blood pressure and impact the potential to gain weight, increasing the risk of heart disease and stroke. Some evidence has also linked poor sleep to an increased risk of developing certain types of cancer and Alzheimer’s disease. 

A lack of sleep may also result in reduced emotional resilience and wellbeing, so we may experience rapidly changing moods, or may notice a detrimental effect on social function and relationships. We may also be more likely to misread facial expression and body language, resulting in us potentially interpreting such information as threatening or negative. 

It is likely that if we do not have sufficient sleep, we could recognise some negative cognitive affects such as a reduction in concentration and memory and difficulty learning new information, making decisions, or solving problems. Our perception and judgement may be altered, and motivation may decrease; this in turn may result in an increase in symptoms of stress, along with a decreased ability to respond to stress. 

Sleep enhances our memory, our ability to learn, our creativity and our ability to solve problems. It impacts on our overall productivity and safety. With insufficient sleep, comes an increased risk of accidents and incidents within the workplace, higher levels of absence and reduced performance.

How much sleep do I need? 

The National Sleep Foundation suggests that adults of working age require between seven and nine hours of sleep per night. 

However, there is no exact ‘right or wrong’ when it comes to how much we need to sleep; some people function well on a little less, whereas others require a little more. 

It is also recognised that our sleep requirements change throughout our lifespan, with younger adults often requiring more sleep than older adults. 

You may wish to consider how healthy and happy you feel after your usual amount of sleep. Do you feel rested and refreshed? Are you productive or do you depend on caffeine and sugar to get you through the day? 

Significant and unwelcome changes to our sleep pattern over prolonged periods could suggest an underlying cause. If sleep duration continues to be far outside the recommended parameters for longer periods, this can pose a risk to an individual’s health and wellbeing. 

If you experience any changes to your sleep pattern which you cannot explain and that last for prolonged periods or impact on your ability to function, then it is recommended you speak to your GP.

How can I improve my sleep?

Sleep hygiene is the term used to describe good sleep habits. It is understood that one of the key principles of sleep hygiene is to maintain a regular routine regarding our sleep/wake cycle.

  • Ideally, we should go to bed and wake each day at the same time, to help maintain our circadian rhythm. Consider monitoring your sleep routine to see where changes could be made. You can download a free Sleep Diary here:
  • Prioritise sleep! Whilst we all push sleep back a little when extra demands are placed on us, this is only likely to have a negative impact on our ability to meet those demands. Make sure you prioritise your sleep. Consider keeping your bedroom just for sleeping, creating a comfortable and soothing environment and making some time for yourself to ‘wind down’ before bed, such as having a warm bath, listening to some relaxing music or meditating. 
  • Try and keep your bedroom cool. A room that is too hot or too cold may result in restlessness and difficulty falling or staying asleep. 
  • Make sure your bedroom is dark! When it’s dark, we release melatonin, a hormone that relaxes the body and helps us to drift off. Try blackout blinds, an eye mask or an alarm clock, with a light that dims gradually. 
  • Additionally, blue light, which is emitted from smart phones, tablets and computers stimulates brain activity, so avoiding this for the hour before bed can have a positive effect on sleep quality.
  • Minimise caffeine intake, avoiding it completely after lunchtime and avoid smoking for 90 minutes before bed. Caffeine and nicotine are stimulants, which increase blood pressure and heart rate. The more caffeine and cigarettes we consume during the day, especially in the afternoon or evening, the greater the risk that this will impact on our sleep. Aim to consume no more than three caffeinated drinks per day; perhaps swap your afternoon coffee for decaf or herbal tea. Consider discussing smoking cessation with your GP or local pharmacist.
  • Avoid heavy meals for 90 minutes before bed. Eating a heavy meal may make you feel sleepy; however, going to bed soon after eating can increase the risk of acid reflux and heartburn. This is because gravity no longer aids the transition of the food when we lay down and the stomach is working harder to digest the meal. Both can result in difficulty falling and staying asleep. If you are used to eating a snack in the evening, aim to make this healthy and light.
  • There is a wealth of evidence to suggest that physical activity can impact our sleep. Moderate to vigorous exercise is understood to help reduce the amount of time we take to fall asleep and decrease the number of times we wake during the night. However, performing intense exercise too close to bedtime may have the opposite effect by increasing heart rate, body temperature and adrenaline levels. Consider altering your exercise routine and monitoring the impact it has on your sleep quality.


For further advice about sleep and tiredness please visit: