Student Article
Why We Sleep: How Rest Helps Our Body and Brain
Immune system (noun): The body's defense against infections and diseases.
Toxin (noun): A harmful substance that can hurt the body.
We spend about one-third of our lives asleep — and science explains why sleep is so important!
Sleep isn’t just rest — it’s power for your brain and body
Sleep is more than just a break from being awake — it’s a powerful process that helps both our bodies and brains stay healthy. While we sleep, our awareness of the world fades, and our brain activity changes.
The four stages of sleep
Sleep comes in four main stages:
N1 — light sleep (you’re just starting to drift off)
N2 — deeper sleep with special brain waves
N3 — the deepest sleep, where your body does most of its physical recovery
REM (rapid eye movement) — your brain becomes active, you start dreaming, and your eyes move quickly (even though your body stays still!)
Each full cycle lasts about 90 minutes and repeats several times a night.
How much sleep do you really need?
Toddlers might sleep 11-14 hours, teens need 8-10, and most adults do well with 7-9. Some people can handle less, but too little or too much sleep can cause problems.
What sleep does for you
Sleep has many benefits. It helps the body grow, boosts the immune system, and clears out harmful toxins from the brain. It also improves learning, memory, and helps control emotions. Scientists think dreaming may help us practice solving problems or facing scary situations.
Sleep may have helped early humans survive
Although sleep makes us less aware of dangers, it may have helped early humans stay safe at night by keeping them still and quiet when predators were around.
Sleep is essential!
In short, sleep is essential for life — even if we don’t fully understand all the reasons why!
© Alice Gregory / Our Media
Immune system (noun): The body's defense against infections and diseases.
Toxin (noun): A harmful substance that can hurt the body.