What Happens to Your Body When You Sleep?

Brian Acton

When you go to sleep, you can let go of your responsibilities and to-do list. But your mind and body are still at work, actively working on mental and physical processes that help you function during your waking hours.

Getting enough sleep is important for your cognitive abilities, mental health, and physical well-being. It can even decrease your risk of developing certain health conditions. This is due in part to all the things that happen when you sleep.

Sleep occurs in four stages:

• Stage 1: Non-REM sleep. This stage occurs during the first one to five minutes of sleep as you’re first dozing off.
• Stage 2: Non-REM sleep. This stage lasts for 10 - 25 minutes while your body subdues a bit more from the initial stage.
• Stage 3: Non-REM sleep. This period of deep sleep relaxes your body even further, and you will cycle through this stage throughout the night.
• Stage 4: REM sleep. Your brain activity picks back up and you may experience your strongest dreams. You will cycle through this stage throughout the night.

During the various stages of sleep, you will go through many changes that promote your mental and physical well-being:

• Body temperature starts to drop as you get ready for bed and sinks to its lowest around two hours before you wake up.
• Breathing slows during non-REM sleep and reaches its lowest levels during deep sleep.
• Heart rate slows during Stage 1 and reaches its slowest pace in Stage 3, then quickens to near its waking rate during Stage 4.
• Muscles gradually relax through each stage of non-REM sleep. Your body stops expending as much energy, reducing your caloric needs as you rest. During the REM stage, your muscles are paralyzed (a condition known as atonia), which prevents you from flailing as you dream.
• Muscles, organs, and other cells repair and chemicals that boost your immune system circulate through your body.
• Brain waves slow down in the early stages of non-REM sleep, but there are bursts of activity in Stage 2 and Stage 3. During REM sleep, which produces your strongest dreams, your brain activity accelerates. REM sleep is thought to enable cognitive abilities and consolidate your memories, while non-REM sleep is believed to play a role in your waking brain processes.
• Hormones are produced, including:
  • Melatonin, which promotes sleep.
  • Growth hormone, which supports bone and muscle development.
  • Cortisol, the stress response hormone.
  • Leptin and ghrelin, which control feelings of appetite and fullness.
• Dreams occur during both non-REM and REM sleep, but the most intense dreams occur during REM sleep.

How to Get a Better Night’s Sleep

A lack of quality sleep can negatively affect your mental and physical health, your mood, and your overall quality of life. Here are some tips for improving the quality and duration of your sleep when you aren’t getting enough:

• Follow a sleep schedule. Go to bed and wake up at the same time every day to help your body maintain its internal rhythm.
• Get a good pillow. The right pillow will properly align your spine and give you the comfort you need to fall asleep and stay asleep. Consider picking up a pillow that promotes proper cervical alignment while you sleep!
• Relax before bed. Take time to do something that calms your mind and body. Avoid the blue light from TV or phone screens.
• Take a bath. When you take a hot bath one to two hours before bed, getting back out causes your body temperature to drop. This mimics the temperature drop your body naturally performs before bedtime, signaling the production of melatonin.
• Get consistent exercise. Working out reduces stress and tires you out, making it easier to fall asleep and stay asleep (just don’t do it too soon before bed).

Getting a good night’s rest is important for your health and your ability to properly function during the day. Take the time and effort to ensure you’re getting the best sleep you can.

Sources:

https://www.nichd.nih.gov/health/topics/sleep/conditioninfo/what-happens

https://www.sleepfoundation.org/how-sleep-works/what-happens-when-you-sleep

https://www.sleepfoundation.org/stages-of-sleep

https://www.webmd.com/sleep-disorders/ss/slideshow-sleep-body-effects