Sleep is essential for our survival. Humans can go longer without food than without sleep.
Sleep is a complex process that involves various stages and cycles. There are typically four stages of sleep, and a complete cycle lasts around 90 minutes.
We spend about one-third of our lives asleep. By the age of 75, we will have spent around 25 years asleep.
Sleep is crucial for memory consolidation. Our brains consolidate and process information during sleep, helping us to retain what we learn.
The amount of sleep we need changes as we age. Infants and young children need more sleep than adults, while older adults may require less.
Our sleep patterns are influenced by our circadian rhythm, which is controlled by a small cluster of cells in the brain called the suprachiasmatic nucleus (SCN).
The blue light emitted by electronic devices such as phones and computers can disrupt our circadian rhythms and make it harder to fall asleep.
Dreams occur during the REM (rapid eye movement) stage of sleep. We typically have several REM periods throughout the night, and they become longer as the night progresses.
Sleep deprivation can have serious health consequences, including an increased risk of obesity, diabetes, heart disease, and stroke.
Some animals, such as dolphins and certain birds, are able to sleep with one half of their brain while the other half remains awake. This is called unihemispheric sleep.
