Does Your Body Heal When You Sleep?
Billions of years ago, before living organisms had brains, they possessed a more crucial key to survival. Despite not having a central nervous system, these creatures were capable of sleeping—and through the process of sleep, their bodies were able to heal.¹
That’s still the case today. Even though humans have evolved way beyond our early origins as aquatic invertebrate animals, we still have one remnant leftover from the organisms we got our start from: we sleep.
Sleep is a fundamental function of almost all organisms in the animal kingdom because it enables the body to replenish in ways that cannot occur while awake. For humans, it is a crucial part of daily life that is critical for our overall health.
When you sleep, your body is able to restore and repair the functions it used when it was awake. Your energy levels have the chance to replenish, your body has time to regrow cells, tissues, and muscles, and you wake up feeling refreshed and ready for the next day. And that’s not all. Everything from how much you weigh to how happy you are is also determined by the quantity and quality of sleep you get.
Without adequate sleep, your body can’t function correctly. And with too much sleep, you are at a greater risk of developing heart disease, stroke, and diabetes.² Here’s why it’s so important to get the right amount of sleep without any form of sleep disturbance so that your body can reap all the benefits.
Sleep promotes bodily healing
When your eyes are closed and you’ve fallen asleep, your body is able to restore itself. Slumber is a time for healing, when your body can attend to any issues, damages, or wear incurred when you were awake.
Various restorative functions occur when you sleep, such as cellular repair, protein synthesis, and tissue growth. Sleep also triggers your brain to release hormones from the pituitary gland, including growth hormones (also known as human growth hormone, or HGH) that influence your height and the strength of your bones and muscles. When you experience nights characterized by inadequate sleep, the healing process cannot begin and your body grows weaker.
Sleep influences your mental health
Because brain activity increases in areas that regulate emotion, sleep can be a vital tool for balancing moods and ensuring emotional stability.³ In fact, sleep plays an influential role in the formation and maintenance of many mental health issues—like depression, schizophrenia, psychosis, and anxiety.
By establishing proper sleep patterns and implementing different relaxation techniques for sleep, your sympathetic nervous system—which is in control of your fight-or-flight response—has a chance to relax. As a result, the levels of stress hormones (or cortisol) in the body plummet during the first few hours of sleep, providing a much-needed break for the nervous system.
After you wake up, your cortisol levels peak once more—providing the body with a surge of energy that leaves you feeling perky, refreshed, and more positive about your day.
Sleep improves your brain functioning
Does your brain heal when you sleep? You bet.
For decades, scientists operated under the belief that animals and humans were born with all the brain cells they’d ever have. That, we’ve since learned, is far from the truth.
Your brain is incredibly active when it’s awake. It is only when you are asleep that the process of neurogenesis—or the formation of new nerve cells in the brain—can occur.
As you rest, waste from the central nervous system is cleared out and toxic byproducts from the brain that build up throughout the day are released. The aftermath of this is a sort of mental lightning that allows your brain to work faster and more efficiently when you wake up.
Memory function is also improved by shut-eye. When you sleep, research suggests that short-term memories are converted into long-term memories as the brain files away information it picked up during the day for later use.⁴
Sleep also helps the brain “empty its trash.” In addition to solidifying memories, all the unnecessary information absorbed throughout the day gets erased or forgotten, to reduce clutter in the nervous system. By improving these functions in the brain, sleep has also been shown to enhance learning, problem-solving, decision-making, creativity, focus, and concentration.
Sleep can affect your weight
People mostly examine their caloric intake and physical activity levels when trying to lose weight. What they often forget is that sleep plays a hand in the number on their scale, too.
As you sleep, your body regulates and manages two types of hunger hormones: ghrelin (which increases appetite) and leptin (which increases the feeling of being full after you eat). When you’re sleeping, your body produces less ghrelin because you’re using less energy than when you were awake.
But if you don’t get enough sleep, the opposite can happen. Ghrelin in the body elevates, and leptin (or the feeling of being nutritionally satisfied) is suppressed. The imbalance that poor sleep patterns can create confuses the body, leading to a much greater risk of overeating and weight gain.
Sleep increases your immunity
A strong and healthy immune system relies on good sleep hygiene. When you get enough rest, your immune system strengthens. When you don’t, this inadequate sleep can make your body more susceptible to germs, making it harder to protect itself from infection.
As you sleep, your body produces white blood cells. Those white blood cells then attack any viruses or bacteria that are currently harboring in your body. Certain antibodies and immune cells are also produced as you sleep to help prevent sickness by joining forces and destroying harmful germs.
Sleep helps you conserve energy
When you sleep, your body is able to replenish the energy that it used while active and awake. While busy doing that, your body can offset additional calorie-burning by slowing your metabolism down. As a result, your body is able to more efficiently replenish its energy stores—while at the same time preserving any remaining energy it has saved from the night before.
Sleep is good for your heart
When you sleep, your heart takes a much-needed break that, for the most part, it isn’t able to do when you’re awake and moving around. With fewer demands made on your heart, your overall blood pressure benefits by dropping to a lower, healthier rate.
When the body is deprived of sleep, the opposite can happen.⁵ Activity in the sympathetic nervous system increases, leading to increased blood pressure and a greater likelihood of developing heart disease later on. High blood pressure makes your heart work harder than normal by damaging your arteries and decreasing the flow of blood and oxygen to your heart.
What’s more, high blood pressure is often considered a “silent killer,” making it unlikely that you’ll notice certain symptoms or signs that you have a problem. However, if you stay on top of a healthy sleep schedule and attain fulfilling rest on a consistent basis, you can lower those risk factors. Wondering how to reset your sleep schedule to help get your body back on track? Read our guide to learn more.
Keys to getting enough sleep
Getting a good night’s rest is essential to living a healthy life. But falling asleep—and staying asleep—isn’t always easy to accomplish.
From meditating to wearing a sleep mask, there are a variety of tools you can employ to both encourage and maintain shut-eye if you’re experiencing sleep problems. Environmental changes (such as hanging up blackout curtains, turning on a white noise machine, and snuggling under a weighted blanket) are some of the more standard solutions for falling asleep.
For something that works faster, ingestible solutions (like chamomile tea or warm milk) can also make a difference. In particular, CBD products have shown a promising effect on improving overall sleep quality and duration. As a sleep aid, the right CBD serving size can help regulate your sleep patterns, allowing the mind and body to wind down sooner. When cannabinoids (such as CBD, CBG, and CBN) are combined with functional ingredients like the sleep hormone melatonin, a refreshing night’s rest is more easily obtained.
Because everyone’s lives and bodies are different, it’s difficult to say how much sleep any individual needs on a given day. Whereas the National Sleep Foundation puts that number at around 7 to 9 hours of sleep a night (for adults), it isn’t always necessary to count.⁶ If you really want to do right for your health, the best thing you can do is listen closely to your body—and give it what it asks for now, not later.