Why do we sleep?

Sleep facts - Why do we sleep?

Sleep, we all do it, but the answer to the question "Why do we sleep?" is not unequivocal to scientists. An average person spends 36% of their life sleeping. That means that when you turn 90, you will have slept for 32 years. Surely those 32 years should tell us that sleep is rather important.

Sleep is defined as a period of inactivity and absence of waking consciousness, during which the body comes to rest. During sleep, physical changes occur in the body: muscles relax, brain waves, heart rate and breathing slow down.

The brain blocks most outside stimuli, lowering our consciousness, and shutting us off from the outside world. Therefore, the idea that sleep serves to restore the body and mind is logical, but probably not entirely true.

Both the brain and our body remain active during sleep, and the heart muscle does not rest either. Indeed, sleep and especially dream sleep consumes energy. Research has shown a link between lack of sleep and weight gain.

To really understand why sleep is so important to us, it is best to look at what happens when we don't sleep or sleep too little. Sleep deprivation negatively affects brain functioning. When you are sleep deprived, you remember poorly, are less creative and more impulsive, and have impaired judgment.

Lack of sleep affects the immune system, which is why tired people are more susceptible to infections. In short, good sleep is the basis for good health.

(source: Russel Foster, Why Do We Sleep)