Why We Sleep?

Pietari Nurmi
Dec 29 · 3 min read

Why do we sleep? That is a good question! The simple answer is that we don't really know. What we do know is that sleep is irreplaceable and something deeply connected to life. All creatures on Earth need to sleep. Without it, they would perish.

Scientists have proposed a couple of theories for the biological purpose of sleep. According to the most popular ones:

1. Sleep fixes the brain

Because we use our brain literally all the time, little wear and tear in the brain tissue is unavoidable. During sleep, the brain has a chance to fix the neuronal damage that occurred during the day and get rid of metabolic waste.

2. Sleep strengthens memory and boosts learning

When we sleep, our brain makes new neural connections and stores the memories we made during the day to our long-term memory. Storing old memories also frees the capacity for new ones the next day, which is essential for learning and memorizing new things.

3. Sleeping keeps your body functioning

Sleep has a significant role in recovery and keeping your body functioning correctly. During sleep, your body, for example, replenishes your hormone storages, fixes tissue damage, and grows new muscle mass.

Even though sleep is crucial for all these things, it is impossible to say which one, or if all of these together, is the fundamental reason why we sleep. The holistic function of sleep has become apparent only recently. So far, we haven't found a single biological process in our body, which wouldn't be improved by a good night's sleep. That is why sleep and sleeping habits play a central role in our quality of life as well as our overall health and wellbeing.

Additional Reading

Walker, M. (2017). Why we sleep: Unlocking the power of sleep and dreams. Simon and Schuster.