WARNING!
This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.
By Dr. Mercola
Lack of sleep has many ramifications, from minor to major, depending on your accumulated sleep debt. Short term, lack of sleep tends to have an immediate effect on your mental and emotional states.
Over the long term, poor sleep can contribute to a whole host of chronic health problems, from obesity and diabetes to immune problems and an increased risk for cancer. Plus it raises your risk of accidents and occupational errors.
Unfortunately, few are those who sleep well on a regular basis. Part of the problem is our propensity for using artificial lighting and electronics at night, in combination with getting insufficient exposure to full, bright, and natural sunlight during the day.
This disconnect from the natural cycles of day and night, activity and sleep, can turn into a chronic problem where you're constantly struggling to sleep well.
Fortunately the remedy is simple, and if you follow the recommendations at the end of this article, chances are you'll be able to reestablish a healthy sleep pattern, without which you simply cannot be optimally healthy — even if you do everything else right.
A Single Night Without Sleep Can Have Severe Implications
As shown in the video above,1 going just one night without proper sleep starts to impair your physical movements and mental focus, comparable to having a blood alcohol level of 0.10 percent.2
In essence, if you haven't slept, your level of impairment is on par with someone who's drunk.
According to researchers, 24 hours' worth of sleeplessness breaks down cognitive faculties to such a degree that you'll be 4.5 times more likely to sign a false confession.3
Overall, you become more susceptible to "suggested" memories, and start having trouble discerning the true source of your memories. For example, you might confuse something you read somewhere with a first-hand experience. According to the authors of this study:
"We propose that sleep deprivation sets the stage for a false confession by impairing complex decision making abilities — specifically, the ability to anticipate risks and consequences, inhibit behavioral impulses, and resist suggestive influences."
Lack of Sleep Linked to Internet Surfing and Poor Grades
Other research4 has linked lack of sleep to more extended internet usage, such as browsing through Facebook rather than studying or working. The reason for this is again related to impaired cognition and the inability to focus, making you more prone to distraction.
Not surprisingly, academic performance also suffers. In one recent study,5 the less sleep high school students reported getting, the lower their average grades were.
How Sleep Influences and Regulates Emotional Perception
Sleeping well is also important for maintaining emotional balance. Fatigue compromises your brain's ability to regulate emotions, making you more prone to crankiness, anxiety, and unwarranted emotional outbursts.
Recent research also shows that when you haven't slept well, you're more apt to overreact to neutral events; you may feel provoked when no provocation actually exists, and you may lose your ability to sort out the unimportant from the important, which can result in bias and poor judgment.
Reporting on this research, in which participants were kept awake for one whole night before taking a series of image tests to gauge emotional reactions and concentration levels, Medical News Today writes:6
"... Eti Ben-Simon, who conducted the experiment, believes that sleep deprivation may universally impair judgment, but it is more likely that a lack of sleep causes neutral images to provoke an emotional response.
The second test examined concentration levels. Participants inside an fMRI scanner had to complete a task that demanded their attention to press a key or button, while ignoring distracting background pictures with emotional or neutral content ...
After only one night without sleep, participants were distracted by every single image (neutral and emotional), while well-rested participants only found the emotional images distracting.
The effect was indicated by activity change, or what Prof. Hendler calls 'a change in the emotional specificity' of the amygdala ... a major limbic node responsible for emotional processing in the brain."
What Happens in Your Body After Two or More Sleepless Nights?
After 48 hours of no sleep, your oxygen intake is lessened and anaerobic power is impaired, which affects your athletic potential. You may also lose coordination, and start to forget words when speaking. It's all downhill from there.
After the 72 hour-mark of no sleep, concentration takes a major hit, and emotional agitation and heart rate increases. Your chances of falling asleep during the day increase and along with it, your risk of having an accident.
In 2013, drowsy drivers caused 72,000 car accidents in which 800 Americans were killed, and 44,000 were injured.7 Your problem-solving skills dwindle with each passing sleepless night, and paranoia can become a problem.
In some cases, hallucinations and sleep deprivation psychosis can set in — a condition in which you can no longer interpret reality. Recent research suggests psychosis can occur after as little as 24 hours without sleep, effectively mimicking symptoms observed in those with schizophrenia.
Sleep Deprivation Decreases Your Immune Function
Research published in the journal Sleep reports that sleep deprivation has the same effect on your immune system as physical stress.8,9
The researchers measured the white blood cell counts in 15 people who stayed awake for 29 hours straight, and found that blood cell counts increased during the sleep deprivation phase. This is the same type of response you typically see when you're sick or stressed.
In a nutshell, whether you're physically stressed, sick, or sleep-deprived, your immune system becomes hyperactive and starts producing white blood cells — your body's first line of defense against foreign invaders like infectious agents. Elevated levels of white blood cells are typically a sign of disease. So your body reacts to sleep deprivation in much the same way it reacts to illness.
Other study10 findings suggest that deep sleep plays a very special role in strengthening immunological memories of previously encountered pathogens in a way similar to psychological long-term memory retention. When you're well rested, your immune system is able to mount a much faster and more effective response when an antigen is encountered a second time.
When you're sleep-deprived, your body loses much of this rapid response ability. Unfortunately, sleep is one of the most overlooked factors of optimal health in general, and immune function in particular.
Sleeping Poorly Raises Your Risk of Type 2 Diabetes
A number of studies have demonstrated that lack of sleep can play a significant role in insulin resistance and type 2 diabetes. In earlier research,11 women who slept five hours or less every night were 34 percent more likely to develop diabetes symptoms than women who slept for seven or eight hours each night.
According to research12 published in the Annals of Internal Medicine, after four nights of sleep deprivation (sleep time was only 4.5 hours per night), study participants' insulin sensitivity was 16 percent lower, while their fat cells' insulin sensitivity was 30 percent lower, and rivaled levels seen in those with diabetes or obesity.
Senior author Matthew Brady, Ph.D., an associate professor of Medicine at the University of Chicago, noted that:13 "This is the equivalent of metabolically aging someone 10 to 20 years just from four nights of partial sleep restriction. Fat cells need sleep, and when they don't get enough sleep, they become metabolically groggy."
Similarly, researchers warn that teenage boys who get too little slow-wave sleep are at increased risk of developing type 2 diabetes. Slow-wave sleep is a sleep stage associated with reduced levels of cortisol (a stress hormone) and reduced inflammation. As reported by MedicineNet.com:14
"Boys who lost a greater amount of slow-wave sleep between childhood and the teen years had a higher risk of developing insulin resistance than those whose slow-wave sleep totals remained fairly stable over the years ...
'On a night following sleep deprivation, we'll have significantly more slow-wave sleep to compensate for the loss,' study author Jordan Gaines ... said ... 'We also know that we lose slow-wave sleep most rapidly during early adolescence. Given the restorative role of slow-wave sleep, we weren't surprised to find that metabolic and cognitive [mental] processes were affected during this developmental period.'"
The Many Health Hazards of Sleep Deprivation
Aside from directly impacting your immune function, another explanation for why poor sleep can have such varied detrimental effects on your health is that your circadian system "drives" the rhythms of biological activity at the cellular level. We've really only begun to uncover the biological processes that take place during sleep.
For example, during sleep your brain cells shrink by about 60 percent, which allows for more efficient waste removal. This nightly detoxification of your brain appears to be very important for the prevention of dementia and Alzheimer's disease. Sleep is also intricately tied to important hormone levels, including melatonin, the production of which is disturbed by lack of sleep.
This is extremely problematic, as melatonin inhibits the proliferation of a wide range of cancer cell types, as well as triggers cancer cell apoptosis (self-destruction).
Lack of sleep also decreases levels of your fat-regulating hormone leptin while increasing the hunger hormone ghrelin. The resulting increase in hunger and appetite can easily lead to overeating and weight gain. In short, the many disruptions provoked by lack of sleep cascade outward throughout your entire body, which is why poor sleep tends to worsen just about any health problem. For example, interrupted or impaired sleep can:
Contribute to a pre-diabetic state, making you feel hungry even if you've already eaten, which can wreak havoc on your weight |
Harm your brain by halting new cell production. Sleep deprivation can increase levels of corticosterone (a stress hormone), resulting in fewer new brain cells being created in your hippocampus |
Aggravate or make you more susceptible to stomach ulcers |
Raise your blood pressure and increase your risk of heart disease |
Promote or further exacerbate chronic diseases such as: Parkinson's, Alzheimer's, multiple sclerosis (MS), gastrointestinal tract disorders, kidney disease, and cancer |
Contribute to premature aging by interfering with your growth hormone production, normally released by your pituitary gland during deep sleep (and during certain types of exercise, such as high-intensity interval training) |
Worsen constipation |
Increase your risk of dying from any cause |
Worsen behavioral difficulties in children |
Increase your risk of depression. In one trial, 87 percent of depressed patients who resolved their insomnia had major improvements to their depression, with symptoms disappearing after eight weeks |
Alter gene expression. Research has shown that when people cut sleep from 7.5 to 6.5 hours a night, there were increases in the expression of genes associated with inflammation, immune excitability, diabetes, cancer risk, and stress15 |
Aggravate chronic pain. In one study, poor or insufficient sleep was found to be the strongest predictor for pain in adults over 5016 |
Tips to Improve Your Sleep Habits
Small adjustments to your daily routine and sleeping area can go a long way toward ensuring you uninterrupted, restful sleep — and thereby better health. To get you started, check out the suggestions listed in the table below. For even more helpful guidance on how to improve your sleep, please review my "33 Secrets to a Good Night's Sleep."
If you're even slightly sleep deprived, I encourage you to implement some of these tips tonight, as high-quality sleep is one of the most important factors in your health and quality of life. As for how much sleep you need for optimal health, a panel of experts reviewed more than 300 studies to determine the ideal amount of sleep, and found that, as a general rule, most adults need right around eight hours per night.
Optimize your light exposure during the day, and minimize light exposure after sunset | Your pineal gland produces melatonin roughly in approximation to the contrast of bright sun exposure in the day and complete darkness at night.
If you're in darkness all day long, your body can't appreciate the difference and will not optimize melatonin production.
Make sure you get at least 30 to 60 minutes of outdoor light exposure during the daytime in order to "anchor" your master clock rhythm, in the morning if possible. More sunlight exposure is required as you age.
Once the sun sets, minimize artificial light exposure to assist your body in secreting melatonin, which helps you feel sleepy.
It can be helpful to sleep in complete darkness, or as close to it as possible. If you need navigation light, install a low-wattage yellow, orange, or red light bulb.
Light in these bandwidths does not shut down melatonin production in the way that white and blue light does. Salt lamps are great for this purpose. |
Address mental states that prevent peaceful slumber |
A sleep disturbance is always caused by something, be it physical, emotional, or both. Anxiety and anger are two mental states that are incompatible with sleep.
Feeling overwhelmed with responsibilities is another common sleep blocker.
To identify the cause of your wakefulness, analyze the thoughts that circle in your mind during the time you lie awake, and look for themes.
Many who have learned the Emotional Freedom Techniques (EFT) find it is incredibly useful in helping them to sleep.
One strategy is to compile a list of your current concerns, and then "tap" on each issue. To learn how to tap, please refer to our free EFT guide. |
Keep the temperature in your bedroom below 70 degrees Fahrenheit |
Many people keep their homes too warm at night. Studies show that the optimal room temperature for sleep is between 60 and 68 degrees Fahrenheit. |
Take a hot bath 90 to 120 minutes before bedtime |
This raises your core body temperature, and when you get out of the bath it abruptly drops, signaling your body that you're ready for sleep. |
Avoid watching TV or using electronics in the evening, at least an hour or so before going to bed |
Electronic devices emit blue light, which tricks your brain into thinking it's still daytime. Normally, your brain starts secreting melatonin between 9 pm and 10 pm, and these devices may stifle that process.
If you have to use your cellphone or computer at night, downloading a free application called F.lux will automatically dim your computer device screens as the evening wears on.17 |
Be mindful of electromagnetic fields (EMFs) in your bedroom |
EMFs can disrupt your pineal gland and its melatonin production, and may have other detrimental biological effects.
A gauss meter is required if you want to measure EMF levels in various areas of your home. Ideally, you should turn off any wireless router while you are sleeping — after all, you don't need the Internet when you sleep. |
Develop a relaxing pre-sleep routine |
Going to bed and getting up at the same time each day helps keep your sleep on track, but having a consistent pre-sleep routine or "sleep ritual" is also important.
For instance, if you read before heading to bed, your body knows that reading at night signals it's time for sleep.
Sleep specialist Stephanie Silberman, Ph.D. suggests listening to calming music, stretching or doing relaxation exercises.18 Mindfulness therapies have also been found helpful for insomnia.19 |
Avoid alcohol, caffeine and other drugs, including nicotine |
Two of the biggest sleep saboteurs are caffeine and alcohol, both of which also increase anxiety. Caffeine's effects can last four to seven hours. Tea and chocolate also contain caffeine.
Alcohol can help you fall asleep faster, but it makes sleep more fragmented and less restorative.
Nicotine in all its forms (cigarettes, e-cigs, chewing tobacco, pipe tobacco, and smoking cessation patches) is also a stimulant, so lighting up too close to bedtime can worsen insomnia.
Many other drugs can also interfere with sleep. |
Use a fitness tracker to help you get to bed on time, and track which activities boost or hinder deep sleep |
To optimize sleep you need to go to bed early enough. If you have to get up at 6:30am, you're just not going to get enough sleep if you go to bed after midnight.
Many fitness trackers can now track both daytime body movement and sleep, allowing you to get a better picture of how much sleep you're actually getting.
Newer fitness trackers like Jawbone's UP3 can even tell you which activities led to your best sleep and what factors resulted in poor sleep. |