Why do we sleep?
No one fully knows why we sleep, but we do know one thing: we can’t live without it. Sleep is a natural part of life that our bodies need every day.
Sleep isn’t just “switching off”. While we sleep, our bodies are busy working. This is when we grow, repair, clear out waste and make sense of everything that happened during the day but behind the scenes a whole range of important processes are taking place.
Sleep plays a big role in both our body and our mind. It helps control our mood, improves memory and focus, and supports our health, weight, and energy levels.
Even one poor night’s sleep can affect how we feel the next day. We may feel tired or sluggish, find it harder to concentrate and remember things, or notice that our reactions and decision-making aren’t as sharp as usual.
Occasional poor nights are a normal part of life and aren’t something to panic about. Our bodies are resilient and sleep can naturally vary from night to night.
However, over time, irregular or poor sleep can lead to long‑term health problems.
If sleep does not serve an absolutely vital function, then it is the biggest mistake the evolutionary process has ever made.”
Rechtschaffen, 1971, p. 88
In fact, every part of the body benefits from good‑quality sleep.
Although science can’t explain exactly why we sleep, it’s clear that nature designed us to need it.
Just like eating well and being physically active, getting good quality sleep is an important part of looking after our health and wellbeing.