On the surface, sleep is simple. You lie down, close your eyes, and drift off. For some people, however, it’s a little more elusive and not so easy to come by.
This is a problem because sleep is an essential biological process. During this state of reduced responsiveness, your body and brain get the space and time they need to undertake critical maintenance functions.
Can’t sleep well? You must do what you can. Drink warm milk before bedtime. Use sleep patches. Soak in a hot tub. Take a warm shower. Just do something, anything, as long as it doesn’t harm your body, to get a good night’s sleep. It’s that important.
What Is a Good Night’s Sleep?
The National Institutes of Health (NIH) says you’re sleeping well if you are consistently getting enough high-quality sleep to support good health. In this context, a good night’s sleep is uninterrupted, regular, adequate, and aligned to the light-dark (LD) cycle.
The following are the four factors that determine sleep health:
- Duration: Most adults need between seven and nine hours of sleep every night. Generally speaking, the younger you are, the more sleep you need. For instance, babies four months to one year old need 12 to 16 hours of sleep, while children three to five years old must sleep 10 to 13 hours per day.
- Quality: Your nightly slumber must be uninterrupted and efficient. Preferably, you’re not waking up in the middle of the night or getting your full eight hours in installments. Sleeping in one whole stretch is necessary to get to the third stage of Non-REM (NREM) sleep, when your body repairs injuries and strengthens your immune system. This stage is crucial to good health and to waking up feeling well rested.
- Regularity: It’s important to establish and stick to a consistent bedtime and wake-up schedule. This establishes sleeping well as a habit.
- Sunlight Exposure: Get some sun in the daytime. Exposing yourself to sunlight during the day will help align your circadian rhythm or internal body clock to your time zone’s light-and-dark cycle.
The Architecture of Rest
Sleep happens in stages or cycles. A healthy sleeper, someone who gets eight or more hours of sleep, typically experiences four to five sleep cycles per night, each one lasting between 90 and 120 minutes.
Sleep cycles are classified into two categories: Non-REM and REM. REM stands for rapid eye movement.
Non-REM (NREM) Sleep
Non-REM sleep has three stages.
- Stage 1 NREM happens when you’re transitioning from wakefulness to sleep.
- Stage 2 NREM is light sleep. This is when you are truly asleep. It happens in multiple rounds, with each succeeding round longer than the preceding one. You need to get to Stage 2 NREM to enter Stage 3 NREM or REM sleep.
- Stage 3 NREM is slow-wave or deep sleep. During this stage, your body restores itself.
REM Sleep
Occurring roughly 90 minutes after you fall asleep, the REM stage is when you experience vivid dreams, which are critical for cognitive functions, emotional processing, and memory consolidation. Like Stage 2 NREM (which is the gateway to REM sleep), REM sleep also occurs in multiple rounds. The first round of REM sleep is about 10 minutes long, and it grows longer (can be up to an hour long) with every iteration.
The Biological Necessity of Sleeping Well
Sleep powers down the body so that cognitive and restorative functions can take over.
Learning: While you sleep, your brain remains active, organizing and sorting information so you can efficiently recall it later. Note: Sleep deprivation can lead to dementia and cognitive impairment.
Physical Recovery and Repair: During deep sleep, physical recovery and immunity reinforcement take place. The body releases growth hormones essential for building muscle and repairing tissues. The immune system can also produce more cytokines to target infections and inflammation. Note: Sleep deficiency can lead to increased susceptibility to sickness.
Cardiovascular Health: During NREM sleep, the parasympathetic nervous system takes over, and your heart rate and blood pressure fall, providing your heart with much-needed rest. Note: Chronic sleep deprivation is linked to hypertension, heart disease, and stroke.
Metabolism: Ghrelin (the hunger hormone) and leptin (the appetite regulation hormone) work in a fine balance to regulate energy and food intake. Lack of sleep disrupts this balance, which increases cravings for fatty, salty, and sweet foods. Note: Lack of sleep is associated with elevated risks for Type 2 diabetes and obesity.
The Dangers of Sleep Debt
When you consistently fail at getting a good night’s sleep, you accumulate a “sleep debt,” which is the deficit between the quantity and quality of the sleep you needed and the quantity and quality of the sleep you got. Sleep debt leads to immediate and long-term consequences.
Short-term: You may experience slowed reflexes, irritability, microsleeps, and headaches. Microsleeps, which are brief moments of zoning out, are particularly dangerous if they happen while you’re operating heavy machinery (e.g., driving).
Long-term: Chronic sleep debt is associated with cognitive impairment, dementia, and metabolic syndromes. Disturbingly, research suggests that even if you sleep in to “pay off” the debt, your metabolism may not fully recover from the damage.
Sleep Well for Better Health
You don’t sleep at night just so you can be awake the next day. You sleep so your body can rest, process the information you learned throughout the day, repair tissue damage and inflammation, target infections, and regulate your metabolism. In short, a good night’s sleep is essential to good health, so make sure you get it.
AUTHOR BIO
Jinky Elizan is a content specialist at SEO Sherpa – Global Best Large SEO Agency Winner, focusing on SEO, PPC, Digital PR, and Search Everywhere Optimization. She has 19 years of experience crafting long-form content on various topics, including health and sleep quality. She also develops WordPress websites in her spare time, enhancing her ability to optimize website copy for reader engagement and action.
