Sleep and Health: Everything you Need to Know

By Lisa Andrews, MEd, RD, LD Published on — Medically Reviewed and Certified by Dr. Robert Kiltz

Table of Contents

Sleep and health go hand in hand. But we often take sleep for granted. For many of us, sleep is less important than our career, housework, social life, and entertainment. But good sleep is just as important to your mental and physical health as exercise, hydration, and a healthy diet. 

The value of sleep for health is a fairly new field of research. Recent science is recognizing that sleep is needed to:

  • refresh energy 
  • maintain critical body functions such as metabolism and fertility 
  • add muscle
  • allow the brain to process information into memories

It’s true that sleep is a time for the mind and body to relax. But while you’re sleeping you are still undergoing vital activities. Your body removes toxins in the brain that collect while awake, repairs muscles that were broken down throughout the day, and consolidates memories.

Sleep is also crucial for emotional regulation. Studies show that prolonged sleep deprivation increases anxiety and depression.

Regular, adequate sleep is also necessary for appetite control, a healthy immune system, normal metabolism, weight management, and fertility.

Circadian Rhythm

Proper sleep habits are important for maintaining your circadian rhythm. This rhythm regulates your daily schedule of sleeping and waking. Your circadian rhythm is your inner biological clock that cycles for 24 hours. This cycle is linked to the function of many critical physiological processes including metabolism, inflammation response, physical exertion, and mental health.

Your circadian rhythm is influenced by the natural cycle of day and night, but also by artificial light and dark. Parts of your brain involved in sleep receive signals from your environment that activate your sleep and wake hormones. These hormones alter your body temperature and metabolism to keep you alert or calm you down in rhythm with the day. 

Disrupting your circadian rhythm with artificial light–from phones, tablets, and screens– sleeping at strange times of the day, not sleeping enough, and eating poorly can alter your internal clock and negatively affect the various processes it regulates.

Your circadian rhythm gets out of synch when you: 

  • pull all-nighters, or work overnight shifts. 
  • travel across different time zones.
  • stay up late as part of a lifestyle routine.
  • take medications that alter sleep hormones.
  • get stressed out. 
  • have a head injury or brain damage. 
  • practice poor sleep hygiene, including an erratic schedule, watching screens within 2 hours of bedtime, drinking too close to bedtime, or have an uncomfortable sleep environment. 

To reset your circadian rhythm: 

  • spend more time outdoors in natural daylight. 
  • practice low impact aerobic movement techniques like yoga or pilates for at least 20 minutes each day. 
  • make sure your sleep environment is dark; blackout shades are fantastic. 
  • Turn off your screens at least 2 hours before bed. 
  • Choose analog media like a book or magazine. 
  • Avoid evening use of alcohol, caffeine, and nicotine.
  • Cut-out afternoon and evening naps. 

Sleep and health for fertility 

Sleep and health are inextricably linked to your fertility.  The quality of your sleep is a significant factor affecting hormone production. Not sleeping enough can cause your body to produce too much of certain fertility hormones, and too little of others.  

These imbalances occur because the part of your brain that’s responsible for regulating reproductive hormones like estrogen and testosterone is the same part that regulates sleep-wake hormones like cortisol and melatonin.  

These same sleep-wake hormones are also connected to the hormones that regulate ovulation in women. When your cycle is off it can be difficult to predict ovulation and time intercourse accordingly. 

For men, inadequate sleep induces sleep-wake hormone imbalances that can interfere with the sperm maturation process. Irregular sperm are less likely to fertilize eggs and may lead to faulty embryos. 

Hormonal imbalances can also greatly decrease your libido while increasing irritability. Both mood issues can make sexual intimacy more difficult, creating a huge barrier to conception. 

Many issues causing infertility are related to underlying disorders like obesity, diabetes, and cardiovascular disease, all of which are exacerbated by poor sleep. 

Sleep and Health: Disordered sleep, sleep deprivation, and risk of disease

The relationship between sleep and health is affected by different stages of sleep. Not all sleep is created equal. While many of us spend at least 8 hours in bed, we’re often not sleeping well. 

Seemingly minor factors, such as how long it takes you to get to sleep, the frequency you awaken at night, and time spent in each stage of sleep, add up to the difference between healthy and unhealthy sleep patterns.

Common sleep and health irregularities

Insomnia

A disorder where a person either cannot fall or remain asleep. It may be due to stress and anxiety, hormonal disturbances (such as menopause), digestive issues, or jet lag. It could also be a symptom of other mental or physiological issues. 

If insomnia persists, it can impact your quality of life and raise the risk of:

  • depression
  • poor concentration
  • mood swings
  • weight gain
  • impaired school or work performance

Up to half of US adults have dealt with insomnia at some point in their lives. Insomnia is most commonly seen in older adults and women. This is because women experience unique hormonal changes, especially during menstrual cycles. Many women on their period report problems going to sleep and staying asleep. 

Insomnia is typically classified as one of these three types:

  • chronic, insomnia that occurs on a regular basis for at least 1 month
  • intermittent, periodically occurring insomnia
  • transient, insomnia that lasts for just a few nights at a time.

Treatment for insomnia

Treatment typically begins with a non-medicated, Cognitive Behavioural Therapy (CBT-i) approach.  

CBT-i focuses on pinpointing anxieties about sleep and changing beliefs, practices, and attitudes associated with these anxieties.  Some of the components common to CBT-i include: 

  • Identifying and increasing behavior that improves sleep, while eliminating problematic behaviors. For example, many specialists recommend going to bed and waking up at the same time. Other strategies include eliminating alcohol and caffeine in the hours before going to bed. 
  • Creating boundaries between sleep and other activities associated with anxiety. Specialists recommend only using your bed for sleep and sex. 
  • Getting up after 10 minutes of laying in bed without falling asleep and returning to bed only when you feel tired. 
  • Keeping your sleep area cool, dark, and quiet
  • Avoiding screens 2-3 hours before bed because the blue light can throw-off your circadian rhythms.
  • Discouraging daytime napping. 
  • Adopting relaxation techniques including breathing exercises, muscle relaxation, and meditation. 

If these approaches don’t succeed, there are a number of sleep aids that can be effective. However, many come with health and lifestyle side effects. 

Melatonin, a supplement of naturally occurring sleep hormone, can be an effective substitute for pharmaceutical sleep aids.

Sleep apnea 

Sleep apnea is a medical condition in which a person stops breathing during sleep. The body will take in less oxygen causing it to wake up. 

There are two types of sleep apnea. The first type, obstructive sleep apnea occurs when the airway space is obstructed or too narrow and air flow stops. The second type is called central sleep apnea. With this disorder, your breathing repeatedly stops and starts while you sleep. This occurs because your brain sends improper signals to the muscles that control your breathing.

Common treatments include lifestyle changes, such as losing weight and quitting smoking. If you have nasal allergies or histamine intolerance, your doctor may recommend medications and dietary changes. For more persistent cases devices and even surgery can be used to open up blocked airways.

Restless leg syndrome

Restless leg syndrome is an overwhelming urge to move your legs when sleeping or trying to sleep. The urge may be coupled by a tingling feeling. Though symptoms usually occur at night, they can also happen in the day.

Certain health conditions such as ADHD (attention deficit hyperactivity disorder) and Parkinson’s disease may be associated with RLS, but the exact reason isn’t always known. Researchers suspect the condition may be caused by an imbalance of the neurochemical dopamine, which sends messages to control muscle movement.

Pregnancy and RLS

Pregnancy or hormonal changes may temporarily worsen RLS signs and symptoms. Some women get RLS for the first time during pregnancy, especially during their last trimester. However, symptoms usually disappear after delivery.

Treatments for restless leg syndrome include many of the healthy sleep habits recommended for general insomnia. 

Other treatments that have shown to be effective include: 

  • Exercise
  • Yoga 
  • Iron and supplementation of vitamine D, C, E  
  • Dopaminergic drugs
  • Foot wraps
  • Pneumatic compression
  • Massage
  • Vibration Pad (relaxis)
  • Near-infrared spectroscopy (NIRS)

How much time should you sleep for good health?

The amount of time you sleep and the health benefits you get from your sleep, depend on a variety of genetic, lifestyle, and age factors. It also changes throughout your lifetime. Though every one of us has our own needs, there are age based-recommendations. 

Here are the general sleep guidelines according to the American Academy of Pediatrics:

  • Older adults (65+): 7–8 hours
  • Adults (18–64 years): 7–9 hours
  • Teenagers (14–17 years): 8–10 hours
  • School children (6–13 years): 9–11 hours
  • Preschoolers (3–5 years): 10–13 hours (including naps)
  • Toddlers (1–2 years): 11–14 hours (including naps)
  • Infants (4–12 months): 12–15 hours (including naps)
  • Newborns (0–3 months): 14–17 hours.

Interestingly, adults who don’t get enough sleep often feel drowsy and sluggish the next day. On the other hand, when children don’t sleep well, they’re often hyperactive the next day. 

Sleep and health tips for parents

A handy tip for parents with children is to put your child to bed earlier. Studies show that children fall asleep faster and stay in bed longer when they go to before 9 in the evening. 

A study looking at toddlers who went to bed before 9 p.m. found that they slept 78 minutes more than kids with a later bedtime. When researchers asked parents of 7-11-year-olds to put their kids to be an hour earlier than usual for only five nights in a row, the kids slept an average of 27 minutes longer each night.

“The earlier the better” is a good rule of thumb for adolescents too. One study revealed that adolescents with a bedtime of 10 p.m. or earlier slept an average of 40 minutes more each night than kids who went to bed by midnight.

Factors that determine your sleep and health needs

Heredity

Genetic mutations may impact how long you need to sleep, the time of day you prefer to sleep, and how you react to sleep deprivation. 

Some people with a specific genetic mutation may only need six hours of sleep, while others may need an average of eight hours. Others with specific genetic mutations may be more negatively impacted by sleep deprivation or experience deeper sleep.

Quality of sleep

How well you sleep can also affect how much you need. If your sleep quality is poor, you may still feel tired despite getting what seemed to be enough sleep. On the other hand, if you’re sleeping well, you may get by with fewer hours. 

9 tips for getting enough ZZs

Having trouble catching enough zzz’s? Not to worry, here are 8 proven techniques for when it’s time to hit the sack:

  1. Stick to a schedule. Go to bed and wake up at the same time every day, even on weekends.
  2. Turn off your screens (including the TV, your phone, tablet, and other electronics) 2-3 hours before bed. Studies show that blue light stimulates your brain and will keep you awake.  
  3. Get regular exercise. At least 30 minutes, 5 days per week is suggested.
  4. Avoid late night eating or alcohol prior to bed. Alcohol may help you fall asleep faster but tends to interrupt sleep.
  5. Avoid caffeine or nicotine after 2 PM.
  6. Keep your room at a comfortable temperature and limit light exposure. Buy blackout curtains if you need them.
  7. Get up instead of lying in bed awake. Read or listen to music in another room, then return to bed when you feel sleepy. 
  8. Avoid the news of social media prior to sleep. Getting excited or aggravated right before bed is a recipe for poor sleep.
  9. Practice boxed breathing–inhale for 4 seconds, hold your breath for 4 seconds, exhale for 8 seconds. Repeat 4 times. This will calm your nervous system and reduce anxiety that may be keeping you awake

Anatomy of Sleep

Sleep is a vital and complex process that impacts how you function in ways scientists are just beginning to understand. What we do know is that there are several key structures within the brain involved in sleep, each with its own effects on our bodies. 

The hypothalamus is a peanut-sized structure far beneath the brain’s surface.  It contains a collection of nerve cells that function as control centers to affect sleep and arousal. Even deeper in the hypothalamus is the suprachiasmatic nucleus (SCN) – groups of thousands of cells that take in information about light exposure straight from your eyes and control your behavioral rhythm. 

When there is damage to the SCN, a person will sleep erratically throughout the day. They are not able to connect their circadian rhythms with the light-dark cycle. 

The brain stem, at the base of the brain is the pons, medulla, and midbrain. These structures are involved in REM sleep and communicate to the body to relax muscles during the dream cycle. Together with the hypothalamus they create GABA, a brain chemical that acts to reduce the arousal centers in the hypothalamus and brainstem.

The thalamus is a part of the brain that passes information from the senses to the cerebral cortex. It also converts information from short- to long-term memory. Throughout most stages of sleep, the thalamus is dormant, allowing you to tune out the outside world. But during REM sleep the thalamus is active in relaying images, sights, sounds and other sensations to the cortex as we dream. 

The pineal gland, a small pea-shaped gland in the brain, takes signals from the SCN and creates melatonin, a hormone that aids in sleep regulation. Individuals who are blind can take small doses of melatonin at the same time every day to regulate their sleep patterns. Peaks and drops in melatonin follow the circadian rhythm as it synchs with daylight and darkness. 

The basal forebrain, near the bottom and front of the brain helps promote sleep and wakefulness. Adenosine (an end product of cellular energy use) gets released in the basal forebrain and promotes the sleep drive. Caffeine blocks adenosine, which increases arousal and may reduce sleep. Part of the midbrain also contributes to arousal. 

The amygdala is an almond-shaped structure involved with processing emotions. It is very active during REM sleep. 

Sleep Stages

The two basic types of sleep are rapid eye movement (REM) sleep and non-REM sleep. Non-REM sleep has three stages. Each stage is associated with specific brain waves and neuronal activity. In a typical night, you go through all stages of REM and non-REM sleep. Towards morning, you experience longer, deeper REM periods of sleep.

Stage 1 non-REM sleep is short, light sleep and involves the transition from wakefulness to sleep. Heartbeat, breathing and eye movements lag and muscles relax. Daytime wakefulness patterns of brain waves slow down. 

Stage 2 non-REM sleep occurs prior to starting deeper sleep and heartbeat and breathing will slow down and muscle will become more relaxed. Eye movements stop and body temperature decreases. Brief bouts of brain wave activity occur although overall brain wave activity decreases.Most of your repeated sleep cycles are spent in this stage. 

Stage 3 non-REM sleep is deep sleep that’s vital to feeling rejuvenated by morning. It happens during the first half of the night in longer bouts. In this sleep, your heartbeat and breathing decrease to their lowest levels. Muscles are very relaxed and it may be hard to arouse you. Brain waves are very slow at this time.

REM sleep initially happens about an hour and half into your sleep cycle. Behind closed eyelids, your eyes are quickly moving from side to side. During REM sleep is when most dreaming happens, though some may be experienced during non-REM sleep. Breathing is fast and irregular and heart rate and blood pressure rise near waking levels. Mixed frequency brain activity is more like that observed in wakefulness. You’re unable to act out in dreams because leg and arm muscles become paralyzed for a short time. Aging reduces the amount of time spent in REM sleep. Non-REM and REM sleep are likely needed to integrate memories.

 

The bottom line on bedtime

Sleep and health are affected by many factors. Good sleep is as important for your well being as good, oxygen, and water. 

When sleep is disrupted due to stress, pain, or other causes, our physical and mental health can suffer in the short and long term.

The best way to ensure you get enough sleep is to modify your bedtime habits and pay attention to your body. Recognize when you’re tired and allow yourself to go to bed. 

Turn off the TV, laptop, tablet, phone and other forms of light exposure. Whatever you think you have to finish at bedtime can wait until the next day. 

Like a delicious ribeye steak, sleep is good nourishing food for both your body and mind. 

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