Why a good night’s sleep is so important

We all know that getting a good night’s sleep is important, and we have all experienced what it feels like after a bad night. And if I were to ask you why this is important you would probably say it is to recharge our batteries. But what does “recharging our batteries” actually mean?
There are many reasons why we need to sleep, because if we don’t get enough it affects our physical and psychological health as well as performance. Chronic sleep deprivation results in severe psychological issues and even hallucinations.

The sleep cycle.

Sleep is made up of cycles which we go through several times a night. These cycles take about 90 to 110 mins. Each cycle is made up of 5 stages each stage taking about 5 to 15 mins.

Stage 1 – light sleep. This is the first stage we go through, occurring between being awake and falling asleep, called hypnagogic sleep.
Stage 2 – this is the onset of sleep, when we start to disengage from our surroundings.
Stage 3 and 4 – this is the deepest sleep and is when the body repairs and restores itself from the wear and tear of the previous day. It is the most recuperative part of the sleep cycle. Tissue damage is repaired. Hormones such as Growth Hormone are released for growth and muscle development. Levels of cortisol increase to help alertness in the morning. It is during this period of sleep that the immune system is at its most efficient for fighting infection.
REM – rapid eye movement. In the adult this makes up 25% of the sleep cycle and uses as much energy as if we were awake. We are completely paralysed during this stage and this is when we dream.

Quality versus quantity.

Both the quality and the quantity of sleep are important. You must know people who say they sleep for at least 10 hours and still feel exhausted. That is because the quality of sleep is not good. Equally, there will be those people who have 6 hours of good quality sleep and also feel tired. They just aren’t getting enough.

So, it is important to get enough good quality sleep. And you can’t play catch up. You can’t go through the week, getting up early and going to bed late due to work, thinking “it will be ok, I can catch up at the weekend”. It doesn’t work like that!

For our psychological and emotional health the most important stage of sleep is the REM stage. It has been found from research on rats, that if they are deprived of REM sleep they will eventually die. If they are allowed to sleep normally after being deprived of REM sleep the proportion of REM sleep increases to catch up with what they lost, forfeiting the other stages of sleep.

In humans, if we are deprived of REM sleep, maybe because we go to bed too late, or have to get up very early the next day, the next night the proportion of REM sleep is increased to make up for what was lost. But that forfeits deep sleep which is important for our physical health.

Why is REM sleep so important?

It is during REM sleep that the brain lays down templates so that we are able to function. This is like uploading files onto your computer so that certain functions may operate. The unborn foetus is in continual REM sleep. It is constantly loading templates ready for when it is born. When born the baby spends 60% sleep in REM, and this slowly decreases to 25% as adults. Every new experience we come across is uploaded as a template. Parents often moan that teenagers spend so much time in bed, lie in late in the mornings. This is because their days are packed with new experiences plus learning at school. In the very elderly REM sleep reduces even further, this is because they have very few new experiences. REM also restores and updates these templates. If this doesn’t happen, we become unstable and vulnerable.

Why do we dream?

Dreaming occurs during REM sleep. Extensive research by Joe Griffin, author of Dreaming Reality, discovered why it is necessary for our survival to dream. We dream to process and clear emotions that have occurred through the day.

It is a bit like doing the dusting. If we don’t dust the ornaments regularly the dust builds up on them. If we don’t dream regularly our emotions build up in our subconscious. We dream in metaphor so that we don’t get confused between reality and our dreams. If we have had an emotionally packed day we will dream more. If something upsets us early in the day, we have all day to process it and resolve it. But if something upsetting happens late in the day, our subconscious tries to resolve it through dreaming. A reason why not to watch the late evening news before going to bed or to go to bed on an argument….

Dreaming also has another function. We often control our behaviour to fit in with social etiquette. If we went round behaving how we really felt, a bull in a china shop, this would cause us a lot of problems. So, when your boss has a go at you, and you really feel like shouting back, you don’t because it may have dire consequences. But at night you will play out how you really felt like behaving discharging those emotions, and it’s done in metaphor.

But dreaming uses as much energy as being awake.

If we dream a lot we may feel tired in the morning. This effects on our emotions. We may feel frustrated or grumpy, or impatient which then affects what happens during the day. This results in more emotions needing to be resolved the next night. The extra dreaming makes us even more tired. This can lead to a vicious cycle which ultimately affects us emotionally and psychologically. Eventually, this may lead to early morning waking, a symptom of “depression”. The brain decides that all this dreaming is just too tiring, so wakes you early to prevent any more dreaming.

So, in essence…..

The key is a good night’s sleep for emotional and physical wellbeing. Anything that disrupts this, such as ill health, chronic pain, or challenging life events, for any length of time, adversely affect it, perpetuating the situation.

Dr Andrea Haas