the importance of sleep

Types of sleep

Many people suffer from lack of sleep. This article explains why a good nights sleep is so essential for physical and emotional health.  We spend a third of our lives sleeping. How we feel and perform when we are awake can depend largely upon the quality of sleep we had the night before. During sleep, your body is working to support healthy brain function and maintain your physical health. In children and teens, sleep also helps support growth and development.


There are two different types of sleep. REM (rapid eye movement) sleep is when we dream, there is also non REM sleep, also called slow wave sleep. During REM sleep there is a paralysis of the anti-gravity muscles and the brains neocortex and emotional Centre’s become aroused.

It is thought that during REM sleep we use large amounts of energy to dream. This isn’t to say that dreaming is a bad thing, clearly it is important and beneficial. Sleep patterns are measured by an electroence-phalogram (EEG). During REM sleep the wave patterns are similar to that when we are awake. For healthy adults, 25% of total sleep should be in a deep trance like state, as when they are in the REM state. REM sleep tends to follow 90 minutes of slow wave sleep, longer periods of REM sleep tend to occur towards the morning.  

As we age REM sleep decreases to around 20% of total sleep, with more frequent waking. It has been hypothesised that the increased use of medication as we age cold be a contributory factor causing insomnia.

A larger and larger proportion of people are suffering from serious insomnia problems. This may cause a whole host of health and emotional complications, affecting every part of life. The ever-connected world of phones, tablets and computers are one possible contributory factor. 

Sleep and health

During waking hours the body is constantly working, proteins are used and degraded, energy systems are used to carry out any work, be it physical or mental. We are bombarded all day constantly with outside stimulus we need to react to. It is during sleep that all the repair and replenishment takes place. Nutrients ingested throughout the day are used to rebuild complex proteins, growth hormones are secreted to aid the repair and rebuilding of muscles and general tissue. Brain neurones are refreshed with sugars to restore energy and the immune system is boosted. It is thought that these processes of resynthesise throughout the body take place during slow wave sleep. It becomes easy to see why sleep is essential to body maintenance and health.

Consequences of sleep deprivation

As already mentioned, sleep plays an important role in your physical health, lack of sleep can have some serious health consequences.

For example, sleep plays an important role in the healing and repair of your heart and blood vessels. Chronic sleep deficiency is linked to an increased risk of heart disease, kidney disease, high blood pressure, diabetes, and stroke. 

A study of teenagers showed that a lack of sleep increased the odds of becoming obese. Sleep deficiency increases the risk of obesity in other age groups as well. Sleep helps maintain a healthy balance of the hormones that make you feel hungry (ghrelin) or full (leptin). When you don't get enough sleep, your level of ghrelin goes up and your level of leptin goes down. This hormone imbalance causes you to feel hungrier.  

Sleep also affects how your body reacts to insulin, the hormone that controls your blood glucose (sugar) level. Sleep deficiency results in a higher than normal blood sugar level, which may increase your risk for diabetes.

Sleep also supports healthy growth and development. Sleep triggers the body to release the hormone that promotes normal growth in children and teens. This hormone also boosts muscle mass and helps repair cells and tissues in children, teens, and adults. Sleep also plays a role in puberty and fertility.

Your immune system relies on sleep to stay healthy. This system defends your body against foreign or harmful substances. Chronic sleep deficiency can change the way in which your immune system responds. If you are suffering from sleep deficiency, you may have trouble fighting common infections. It's also been shown that just one night of 4 to 5 hours sleep can cause your natural killer cells (those that fight cancer) to drop by 70%.

Studies show that a good night's sleep improves learning. Whether you're learning maths, how to play the piano, how to perfect your golf swing, or how to drive a car, sleep helps enhance your learning and problem-solving skills. Sleep also helps you pay attention, make decisions, and be creative.

Studies have shown sleep deficiency alters activity in some parts of the brain. If you're sleep deficient, you may have trouble making decisions, solving problems, controlling your emotions and behaviour and coping with change.

Children and teens that are sleep deficient may have problems getting along with others. They may feel angry and impulsive, have mood swings, feel sad or depressed, or lack motivation. They also may have problems paying attention, and they may get lower grades and feel stressed.

There has been plenty of evidence to suggest that lack of sleep can contribute to psychological conditions such as depression, anxiety, psychosis and suicide.

It is interesting that when we are unwell with an infection or fever we sleep more. Even when we are asleep without a fever, our immune function works harder than when we are awake. This explains why many groups of people who are prone to sleep deprivation (junior doctors and other shift workers), suffer more illness and infection than the general population. And why people suffering depression and stress because of the death of a partner are more prone to serious ill health.

Even minor tasks can be impaired by lack of sleep, there are more studies to show that driving ability can be affected by lack of sleep as much as or even more than by being drunk. It has been estimated that sleepy drivers account for 100,000 car accidents each year. It becomes easy to see how sleep deprivation can put pressure on other aspects of your life, like work and relationships.

How much sleep is recommended?

Sleep is important to every age group, however the younger you are the more you will need. This is mainly down to the need for energy to repair and grow. As a rough guide, the following details how many hours sleep different age groups should be getting each night:

  • New-born babies - 16-18 hours per day

  • Toddlers - 11-12 hours

  • 4-12 year olds - at least 10 hours

  • Teens - 9-10 hours

  • Adults/elderly - 7-8 hours

It has been hypothesised that sleep depravation builds up. If you lose 2 hours of sleep per night you will be in 14 hours of “sleep debt” per week. Some may choose to take naps during the day to make up for the loss of sleep, however the sleep quality is not comparable. If you are feeling tired throughout the day, it is a sign you may not be getting enough sleep. 

It seems simple, but its always a good idea to sleep when you are tired, rather than overriding the sleep sensation to stay awake.

Many different things can cause sleep deficiency. You may have a job that requires you to work long, unsociable hours. Your job may be highly stressful, keeping you awake at night. Relationship worries, money problems, nutrient deficiencies, too much caffeine, medication, pain or health problems, anxiety, a newborn baby, the list goes on.

How can you get more sleep?

  • Make a conscious effort to switch your brain from a busy beta wave state to a relaxed alpha state. Use the hour before you sleep to relax, don’t do any work and turn off bright lights (computers, phones, televisions).

  • Allow time to get the required amount of sleep. Try to go to bed and wake up at the same time everyday, as keeping to a routine as much as possible can help. Staying up late and then sleeping in late can disrupt the whole week.

  • Exercising on a regular basis can help with sleep patterns, though you should avoid exercising late at night. Aim to be physically active during the day to 'tire' yourself out.

  • Meditation has been shown to help people with sleep insomnia, as have relaxation tapes and self hypnosis.

  • Keep the place you sleep quiet, cool and dark.

  • Taking a bath before bed has been shown to help relaxation.

  • Napping may be necessary for some people, however it can prevent you getting to sleep later. Try not to nap after 2pm and keep naps to 20 minutes. Obviously napping in young children is perfectly normal and healthy.

  • Try drinking chamomile tea before bed.

  • The mineral magnesium and calcium are natural tranquillisers, and have been shown to aid sleep.

  • Some herbs have been shown to enhance sleep patterns, including valerian and passiflora.

Sleeping pills - In desperate times prescription sleeping pills may help, but it important to be aware they can become addictive, so you should limit them to the odd occasion. Chronic use of sleeping pills can also affect your memory. What time you wake can be an indicator as to what may be causing the insomnia. Waking between 3-5am indicates adrenal exhaustion from stress, whilst waking between 1-3am is thought to be due to a struggling liver (click here to read more about liver health).

Foods & mealtimes - avoid large, heavy meals at least 2 hours before bed, especially those high in protein as these can wake the brain. Although a large meal can make you feel sleepy, it can cause you to wake later in the night due to the way in which it is metabolised. You should also avoid stimulants, like caffeine (chocolate, coffee, tea, soda) and nicotine, as they interfere with sleep. I would suggest completely, but if that's not possible, try not to consume any of these stimulants after 3pm in the afternoon. Do this gradually, as caffeine withdrawal can cause headaches. A healthy liver can help by eliminating and detoxifying medication and caffeine. Avoid too much cheese later in the day. Cheese contains amino acids, which keep you awake. It is worth keeping a food diary to see if there are any links between food and trouble sleeping. Food intolerances or allergies may contribute, if not be a potential cause. 

A meal high in starchy carbohydrates (pasta, brown rice, potato’s) can help encourage the body to produce a brain chemical called serotonin, which can help reduce anxiety and improve quality of sleep. Serotonin is produced from an amino acid called tryptophan (found in fish, turkey, chicken, cottage cheese, beans avocado’s, banana’s and wheat germ). Including these foods in your diet will ensure you have the right amino acids needed to produce this important chemical. The starchy carbohydrates increase insulin that helps drive the tryptophan across the blood brain barrier. Most amino acids are taken into the individual cells when insulin increases, but tryptophan is left behind, binds to albumin which increases its chances of being taken to the brain for conversion to serotonin.

This article has
been written by
Terry Fairclough