To Sleep, Perchance to Dream
In these hyper-busy, technology-driven modern times, many people have come to think of sleep as a luxury, as merely an end-of-the-day rest-stop between packed schedules. Some individuals even brag about being able to function at a high level with as little as four hours of sleep a night. Well, those outliers likely fall into one of three categories: they are either taking stimulants to artificially ward off sleep, are in the manic phase of bipolar disorder, or are genetic freaks of nature because sleep is just as necessary to good health and the body's physical/mental functioning as oxygen, food, water and shelter. Indeed if sleep wasn't absolutely essential, why does every animal in the world partake in this activity that leaves many vulnerable to predators in the wild? The consensus of the health and science community is that adults need 7-8 hours of sleep per night, teens and adolescents require 8-9 hours and children 10-12 hours to ensure proper mental and physical conditioning, growth and development and a healthy lifestyle, yet many don't accomplish this for several reasons. The remainder of this post explains some of the aspects of why sleep is so important and not just a luxury.
I know quite a bit about the harms of sleep deprivation, both from my experiences as a medical resident and my suffering the effects of obstructive sleep apnea. I will discuss this issue in next week's blog entry, but being that I am not an expert in sleep physio-logy, I will instead rely directly on the information provided by a few credible and prestigious organizations. The first thing to know about sleep is that it not a singular activity, but rather a cycle of five stages. the first four stages are known as non-REM sleep, with stage I being a very light sleep just beyond consciousness, and stages II-IV progressively becoming a deeper sleep. REM or rapid eye movement sleep occurs when the body is fully relaxed and the mind enters the dream state.
According to ResMed (www.resmed.com): "NREM sleep typically occupies 75–80% of total sleep each night. Many of the health benefits of sleep take place during NREM sleep – tissue growth and repair occurs, energy is restored and hormones that are essential for growth and development are released.
REM sleep typically occupies 20–25% of total sleep each night. REM sleep, when dreaming occurs, is essential to our minds for processing and consolidating emotions, memories and stress. It is also thought to be vital for learning, stimulating the brain regions used in learning and developing new skills."
Many people may be mistaken that sleep is a completely passive period of rest for the body, when in fact sleep is a time when several critical physiological activities are taking place. Humans, as well as all other animals simply cannot function properly without adequate sleep (albeit the required amount varies by species and age. The following facts constitute the most important aspects (albeit not an exhaustive list) of sleep's benefits.
According to the National Heart, Lung and Blood Institute (www.nhlbi.nih.gov):
"Sleep helps your brain work properly. While you're sleeping, your brain is preparing for the next day. It's forming new neural pathways to help you learn and remember information. Studies show that a good night's sleep improves learning. Whether you're learning math, how to play the piano, how to perfect your golf swing, or how to drive a car, sleep helps enhance your learning and problem-solving skills. Sleep also helps you pay attention, make decisions, and be creative."
"Sleep plays an important role in your physical health. For example, sleep is involved in healing and repair of your heart and blood vessels. Ongoing sleep deficiency is linked to an increased risk of heart disease, kidney disease, high blood pressure, diabetes, and stroke."
"Sleep deficiency also increases the risk of obesity"... because "sleep helps maintain a healthy balance of the hormones that make you feel hungry (ghrelin) or full (leptin). When you don't get enough sleep, your level of ghrelin goes up and your level of leptin goes down. This makes you feel hungrier than when you're well-rested."
"Sleep also supports healthy growth and development. Deep sleep triggers the body to release the hormone that promotes normal growth in children and teens. This hormone also boosts muscle mass and helps repair cells and tissues in children, teens, and adults. Sleep also plays a role in puberty and fertility."
"Your immune system relies on sleep to stay healthy. This system defends your body against foreign or harmful substances... if you're sleep deficient, you may have trouble fighting common infections."
There is plenty more information about the physical and mental benefits of sleep, and I encourage readers of this blog entry to learn more if you are interested by perusing other websites or reputable sources of knowledge concerning sleep physiology. But I will stop here because I think I have captured the most important reasons for why adequate sleep is essential. Next week I will delve into the dangers of sleep deprivation, including how it contributed to ruining my career as a physician and nearly ended my life prematurely.