If you’re having trouble sleeping at night, you’re likely familiar with the crankiness and fatigue that comes the next morning. Here’s what’s happening to you internally.


Sleep is important for everybody. Even for those who think they don’t have time for sleep or believe life limits the amount of time they can possibly have, there are steps you can take to fall asleep faster, maximize that time, and sleep better.

But first, let’s get into its physiology and learn how sleep deprivation affects us.

As you may be familiar, sleep happens in stages through a cycle. You’re not getting deep sleep the whole time you’re out, but each sleep stage is important in different ways. In a nutshell, when you first fall asleep, you go through NREM (non-rapid eye movement and REM (rapid eye movement) stages: NREM1, NREM2, NREM3, and REM. You fall deeper into sleep as you progress through the stages, and REM sleep is the stage at which dreams occur. As you’re asleep for longer, you spend more time in NREM3 and REM.

The whole cycle can take 90-120 minutes, with ~4-5 cycles in a night. This variation in cycle length is why some people feel better on less sleep than others – their sleep cycles are likely more “efficient” and take less time.

You may believe that our brains “turn off” and enjoy the rest; however, in reality, your brain is actually using the energy it would normally use to be conscious to fine-tune your biology. Here’s a sample of your brain’s to-do list while you’re snoozing:

  • Cementing new memories and cleaning out unused, unneeded ones
  • Your body relaxes, and your blood pressure and temperature drop
  • You make and release growth hormone
  • Hunger (leptin + ghrelin) hormones are regulated

So what happens from when we don’t get enough sleep?

A dysregulation of hormones and other biological factors can occur and cause a cascade of other symptoms.

IL-6, a cytokine that helps regulate your immune system, is typically low during the day/high when we sleep. However, without enough sleep, its daytime levels can increase and stimulate our hypothalamic-pituitary-adrenal (HPA) axis. This, in turn, leads to an increase in cortisol, the stress hormone.

This is especially important to know for those who exercise early in the morning. While exercise is typically a positive stressor and lowers your cortisol, if you don’t get enough sleep, your baseline cortisol is already high – and exercise becomes a negative stressor. Don’t work out if you don’t sleep well! Bottom line: it’s physiologically stressful and inflammatory if we keep getting inadequate sleep.

Hormones, such as those associated with growth and appetite, are also impacted during sleep. A tell tale indicator in which growth hormone is affected by interrupted or inadequate sleep is the fact that children with sleep apnea have stunted growth. In adults, growth hormone helps regulate metabolism, so it’s still important and worth prioritizing sleep.  Sleep deprivation has also been associated with low leptin (the fullness hormone) and high ghrelin (the hunger hormone): this means we’re more hungry if we don’t sleep enough.

Here are a few ways to help you fall asleep faster and sleep better:

  • Invest in blackout curtains
  • Put cozy sheets on your bed
  • Charge your phone across the room (or outside of it), and use an old-fashioned alarm clock
  • Create a quiet environment by picking up a white noise machine or putting in earplugs
  • Only use your bed for sleep and sex
  • Turn off screens and blue lights at least 30 minutes before bed
  • Avoid caffeine after 2pm
  • Try a sleep-centered guided meditation
  • Create a bedtime or wind-down routine to help signal your body and mind every night that it’s time to rest

Here’s to a better night’s sleep tonight!

Adapted from the original article.

Amy Hanneke, RDN, LD is an Idaho-based Registered Dietitian and owner of Satisfy Nutrition.  Through an anti-diet approach in her nutrition coaching practice, Amy firmly believes in helping individuals live a life without restrictions, full of joy, self care, and delicious food. Learn more about Amy at Satisfy Nutrition.