Updated: Oct 26, 2022
It’s not about the number of hours you sleep, but about your quality of sleep.
Co-authored by Gerda Venter
When patients come to me to address the root cause of their illness, we often address their sleep first. Sleep is vital for overall health and wellbeing. It is as essential to your survival and wellbeing as food and water. It impacts nearly every aspect of your body, affecting the brain, heart, and lungs, as well as metabolism, mood, and your immune system. Physical, emotional, and mental health all depend, in part, on good sleep. Your body has an incredible ability to heal itself when you allow it. Healing often takes place when you sleep.
When you do not get enough sleep, you become sleep deprived. In the short term, sleep deprivation affects your mood, judgment, and ability to focus. While sleep-deprived, you might have trouble remembering things and be more prone to make errors at school or work. In the long term, lack of sleep is associated with chronic health problems like diabetes, high blood pressure, stroke, obesity, depression, and heart and kidney disease.
What happens when you sleep?
As you sleep, your brain works to physically repair your body and encode memory. In the process, your brain also flushes out waste that accumulates during your waking hours which may contribute to neurodegenerative diseases. In simple terms, you increase your risk for dementia later in life if you don’t sleep enough now.
Your body has a circadian rhythm to help you know when to sleep and when to wake up. Circadian rhythms are internal cycles that run on a roughly 24-hour schedule, much like the earth’s rotation. Your circadian rhythm is regulated by the hormone Melatonin. Melatonin is produced by the pineal gland in the middle of your brain. Sunlight entrains your circadian rhythm, impacting when you want to sleep and when you are awake. When you are exposed to less light, such as in the evening, your melatonin levels rise, and you feel sleepy. When you are exposed to more light, melatonin falls and cortisol rises, so you feel alert and awake.
Adenosine is a neurotransmitter that transfers energy and signals throughout the body during the day. When your body runs out of fuel from food, adenosine signals to the body to become drowsy to sleep and rebuild your energy reserves. During sleep, the build-up of adenosine gets broken down again, leaving you refreshed in the morning.
The 5 phases of sleep
During sleep, you usually pass through five phases. For a good night's sleep, your body needs to cycle through all five stages of sleep at least five times (5x 90min = 7.5h.) Each stage has a different function. These stages of sleep progress in a cycle from stage 1 to REM (Rapid Eye Movement) sleep, starting with stage 1 each time.
During stage 1, which is light sleep, you drift in and out of sleep and can wake up easily.
When you enter stage 2, your eye movements stop and your brain waves become slower, with occasional bursts of rapid waves called sleep spindles.
In stage 3, extremely slow brain waves called delta waves begin to appear, interspersed with smaller, faster waves. Your brain waves slow, and blood is redirected from your brain to your muscles, allowing your body to heal and repair itself. Your muscles relax. Your blood pressure decreases and your breathing rate decrease. Here is where your deepest sleep occurs.
By stage 4, the brain produces delta waves almost exclusively. It is very difficult to wake someone during stages 3 and 4, which together are called deep sleep. There is no eye movement or muscle activity.
Stage 5 is when you experience REM sleep. Your brain becomes more active, your body becomes more relaxed and immobilized. This is the phase when dreams occur, and your eyes move around quickly.
A complete sleep cycle takes an average of 90 to 110 minutes. The first sleep cycles each night contain relatively short REM periods and long periods of deep sleep. As the night progresses, REM sleep periods increase in length while deep sleep decreases. By morning, you will spend nearly all your sleep time in stages 1, 2, and REM.
How much sleep do you need?
Most people need between seven and eight hours of sleep a day, although some people may need more or less. On average women need more sleep than men. Too often people feel that nighttime is the only time they get to do work or exercise. So, they cram in as much work as they can after their children are asleep and before their children wake up. Even though this might be the best time for you to get work done, it is also the best time for your body to get restoration work done.
If you don't get enough sleep, you will start to feel tired and irritable and your performance at work or school will suffer. Not sleeping well does not only affect the next day but also the following couple of days.
When should you sleep?
Often patients tell me they're a night owl and do not feel like sleeping before midnight, or that they adjusted their sleep schedule to be up at night and sleep during the day. I have been working overnight for years in the Hospital, Emergency Department and Labor & Delivery Unit, delivering babies at any hour, so I too can not adhere to a normal sleep schedule.
Unfortunately, studies have shown that your body repairs the most between 10 pm and 2am, irrespective of preference. Even if you did get 8 hours of sleep from 12pm to 8am, it will not be as restorative as sleeping from 10 pm to 6 am. During the earlier hours of the night, your body spends more time in non-REM sleep, the deepest stage of sleep, when your body restores and recovers. Later during the night, the length of your non-REM sleep decreases while the duration of lighter, less restful REM sleep increases.
How long should it take to fall asleep?
On average, it should take you about 20 minutes to fall asleep. If falling asleep regularly takes more than 30 minutes, that might be a sign of a sleep disorder like insomnia. Trouble falling asleep could also be the result of poor sleep habits, such as ingesting caffeine late in the day, looking at your smartphone in bed, or following an irregular sleep schedule.
If you still are not asleep after lying in bed for a while, I recommend getting out of bed. Doing a quiet activity in another room until you feel more tired can help prevent your brain from associating your bed with a place of unrest.
On the other hand, consistently falling asleep the moment you get into bed could be a sign of sleep deprivation. Not getting enough sleep regularly can cause excessive tiredness, making you fall asleep quickly.
Sleep deprivation has been linked to developing chronic diseases such as obesity, heart disease (increases your risk by 48%), cancer, arthritis, overactive/underactive thyroid, stroke, and Alzheimer’s dementia. It triples your risk for type 2 diabetes. It depresses your immune system. Did you know that you are 4 times as likely to get a cold when you are sleep deprived?
The most obvious sign of sleep deprivation is excessive tiredness. Other warning signs of sleep deprivation include:
Dozing off while driving, working, watching TV, or reading
Difficulty focusing, learning, or problem-solving
Slower reaction times
Trouble remembering things or making decisions
Making more mistakes at school or work
Behavioral problems in children, such as increased impulsivity, anger, or mood swings.
How to get optimal sleep
Your physical, emotional, and mental health all improve with better sleep. Even minor lifestyle changes can lead to more restful sleep. Try the following to ensure a good night’s sleep:
1. Go for a walk early in the morning
Your body is designed in such a way as to get going early in the morning. The best way to get going, literally better than a cup of coffee, is to go outside for a walk. Your body needs sunlight in the morning, if it is completely dark or significantly overcast, some people do well with a Sunlight light on for 20min in the morning.
2. Do not disrupt your circadian rhythm
For optimal sleep, your body needs it to be dark 2-3 hours before bedtime. Unfortunately, your computer and cellphone screens disrupt your circadian rhythm. Instead of reading on your phone, try writing a to-do list for tomorrow before you go to bed. This reassures your mind that specific issues will be dealt with, and your mind does not have to try to remember them during the night.
3. Prepare your bedroom environment
Keep your bedroom cool, dark, and quiet as possible to promote sound sleep. It may help to block out light by removing electronics and using blackout curtains or an eye mask. A white noise machine can help minimize disturbances from outside noises. It is also important to invest in a mattress, pillow, and bedding set that makes you feel comfortable.
4. Follow a regular sleep schedule
Go to bed and wake up at the same time every day. The more consistent your sleep schedule, the easier it will be for you to naturally feel tired and alert at the right times. In older adults, following a daily routine, in general, is also associated with better sleep.
5. Carefully choose foods and drinks
A sleep-friendly diet includes a variety of foods, with adequate protein and fiber. Avoid eating anything too spicy or fatty close to bedtime to prevent heartburn or acid reflux from interfering with your sleep. Caffeine -molecules are shaped like adenosine, the neurotransmitter that needs to tell your brain you are tired. Caffeine has the incredible ability to keep your brain and body from realizing it is tired. Coffee has a half-life of about 5-7 hours. This means, that for caffeine to be adequately metabolized for you to fall into your deeper more restful sleep stage (non-REM 3) it is best to avoid all caffeine in the afternoon.
6. Prepare your body and mind for sleep
Meditation helps to activate your parasympathetic nervous system which allows your body to fully relax. Try making yourself a cup of herbal caffeine-free tea. Chamomile tea works great. You can also warm oat milk with cinnamon and honey. Also, take a warm bath with Epsom salts and lavender essential oil.
Sleep influences every function in your body. It affects how your body processes food, how it regulates blood sugar, processes cognitive information, and it reduces inflammation. Optimizing your sleep is critical for optimal health. Getting enough good quality sleep at the right time can help you feel your best and be high functioning every day.