Don't be surprised that there are so many prevalent myths about sleep.

Modern sleep research only began in the mid-20th century, with the landmark discovery of REM sleep in the 1950s .

Before this time, sleep was widely considered a " passive process " and therefore, not of much interest to scientific research.

So, when it comes to actual "facts" about sleep, this relative lack of empirical evidence has led, over the years, to a disproportionate amount of household advice and folk wisdom that still accompanies us today.

Although there are many mysteries about sleep that have yet to be solved, the good news is that in recent decades, science has managed to make an important distinction between fiction and fact.

Here is a summary of some of the scientific research behind the 17 more common myths and misconceptions about sleep.

Myth 1: Sleep is a passive activity

For a long time, sleep was considered a "dead time" for the body - a state where the individual ceased to be conscious.

In reality, however, sleep is largely a very active state where a complex sequence of events occurs and follows a cyclical pattern every night. Although we remain still and inactive when we sleep, there are many homeostatic processes - vital - that occur every night, but we are unaware of them.

Certain brain activities, such as delta waves, increase when we sleep. Sleep is also a time when the endocrine system increases production of human growth hormone and prolactin, which are crucial for a healthy immune system.

And let's not forget our dreams. Dreams are believed to be vital for consolidating long-term memories and creating neural connections.

Myth 2: Adults need less sleep

Another common misconception is that as we age, we naturally need less sleep. While it's true that older adults tend to experience more disrupted sleep patterns, this can be a result of other health issues and the shift in circadian rhythms as we age.

Professor Sean Drummond of the University of California stated that:

"Older people benefit from sleeping as much as they did when they were in their 30s. This varies from person to person, but whatever you slept at 35 should be the same by 75. The problem is that people have trouble sleeping as they get older and think that's a sign that they need less sleep, but that's not true."

Myth 3: You can catch up on sleep on the weekends

If you've had a busy week of work and social obligations, then it's very likely that you've built up a " sleep debt ."

A common belief that still prevails in our society today is that you can make up for the hours you lost during the week by sleeping more hours on the weekend.

However, some research has shown that this may not be sufficient for your full recovery for the following week.

A recent study showed that while a long sleep can restore your performance to normal levels, this positive effect may only last for the next 6 hours after you wake up.

As the day progresses, reaction times become about 10 times slower than they were earlier, increasing the risk of accidents and errors.

Dr. Elizabeth Klerman, a professor in the Department of Sleep Medicine at Brigham and Women's Hospital, concluded that:

"Individuals who get too little sleep during the work or school week but try to make up for it on the weekends may not realize that they are accumulating a chronic sleep debt."

Myth 4: Snoring is harmless

According to a 2005 poll by the National Sleep Foundation, 32% of adults in America suffer from snoring at least a few nights a week (unfortunately, there is insufficient data for Greece).

However, if you suffer from chronic snoring, it could be a symptom of a serious, even life-threatening condition known as obstructive sleep apnea syndrome (OSAS).

OSAS is characterized by pauses in breathing during sleep, which are caused by airway obstruction. If neglected and undiagnosed, OSAS can reduce oxygen levels in the blood and put strain on the heart and respiratory system, increasing the risk of high blood pressure, stroke, and even heart attack.

Myth 5: Sleeping pills are harmless

Sleeping pills are among the most commonly prescribed medications in the world. It is estimated that up to 10% of the US population received medication for sleep disorders in 2010, while for Greece, unfortunately, there is not enough data.

However, a recent large-scale study has asked doctors to reconsider how we treat people with sleep disorders. “Sedative” drugs, which include common sleeping pills such as tamazepam and zolpidem, were shown to be associated with a significantly higher risk of death and cancer. The report concluded that:

"Taking prescription sleeping pills was associated with a more than threefold increased risk of death even when fewer than 18 pills/year were prescribed."

Myth 6: You are productive even with 4 hours of sleep

Margaret Thatcher, the former Prime Minister of the United Kingdom, proudly stated in an interview that she only needed 4 hours of sleep a day to function properly.

Recently, scientists discovered a gene that may explain why some people can get by on much less sleep than we normally need, but this is only true for 2-3% of the population.

The rest of us need an average of 7-8 hours each night to stay fit, healthy, and alert during the day. The consequences of sleep deprivation can be very serious indeed. Sleep deprivation can cause many negative side effects, including heart disease, depression, and weight gain, to name a few.

Myth 7: Television helps you sleep

If you like to watch TV before bed, you're not alone.

Often used as a sleep aid, the flickering light and constant ambient noise cause enough mental distraction to calm a busy mind before falling asleep.

However, research has shown that sleeping with the TV on can cause many health problems, including depression.

Also, the television emits blue light which prevents the secretion of melatonin, the sleep hormone. When the body is exposed to blue light, it stops producing melatonin, wakes us up and prevents us from falling asleep naturally and in a short time.

Myth 8: Drinking alcohol helps you sleep

Alcohol has a natural sedative effect, so it might seem logical that a glass of wine, whiskey, or beer before bed would help you fall asleep faster.

Although it may help you fall asleep faster, as alcohol metabolizes through your body during the night, your sleep becomes progressively lighter as it activates the sympathetic nervous system (the one responsible for our survival - also known as "fight or flight"), causing you to wake up in the middle of the night.

Research has shown that alcohol affects sleep in several ways, affecting protein channels in the brain that are responsible for regulating our sleep cycles.

Chronic drinkers develop a tolerance to these effects, increasing periods of light sleep, including the REM phase, while decreasing the amount of deep, restorative sleep.

Myth 9: Teenagers are lazy and love to lie in bed

A common assumption is that teenagers are lazy, moody, and unmotivated when it comes to getting out of bed in the morning. Well, research shows that there are real biological factors that explain these types of behaviors.

Starting around the time of puberty, a shift in the body clock occurs. During the teenage years, there is a 2-3 hour delay in circadian rhythms and children of this age, especially boys, gradually become more “evening types.”

[Read: What is circadian rhythm and how do you regulate it ?]

This phenomenon is known as delayed sleep phase disorder and is characterized by delayed sleep-wake timing.

Studies have also shown that teenagers actually need about 9-10 hours of sleep as opposed to an average of 7-8 hours for most adults.

Read: How many hours of sleep do you really need? ]

Myth 10: Napping is a waste of time

In many Western societies, the concept of napping is viewed with indifference, even negativity. However, napping should be given more respect, as it can significantly improve your performance at work.

[Read: Why is success linked to naps? What does science say? ]

In some parts of the world, the culture of napping has been embraced in workplaces. In Japan and the In Korea , workers are encouraged to take a midday nap to increase their productivity. This trend has also been adopted by some of the world's largest technology companies, such as Google and Uber .

And if you still think that naps are only for the lazy, think again, among the celebrities who loved naps throughout the centuries are Einstein, Thomas Edison, John F. Kennedy and Bill Clinton.

Myth 11: Never wake a sleepwalker

It can be quite alarming to discover that a loved one or family member is sleepwalking. Such nocturnal activities can range from a simple nighttime walk around the house to more complex actions, such as driving or using a computer.

Although we are beginning to understand the causes of sleepwalking, much of our current knowledge has been clouded by urban myth and fiction from books and movies.

One of the commonly held beliefs is that if you wake someone up while they are sleeping, you will cause them such a shock that they may suffer a heart attack or even die. While it is true that waking a sleepwalker can cause some distress, there is no documented evidence to prove that it can be fatal.

Myth 12: Everyone needs 8 hours of sleep

Scientific studies over the years have proven that we are not all the same when it comes to the amount of sleep we need to function optimally the next day.

Our sleep requirements vary throughout our lives. For example, 16 hours is normal for a newborn, but not for an adult.

There may be a genetic link that explains why some people can thrive on less than the recommended amount of sleep , but most of us need, on average, 7 to 8 hours of sleep each night.

Interestingly, if we deviate from this norm of 7 to 8 hours, there are consequences for us as sleep deprivation has been shown to have many negative effects on our health and well-being.

However, it's possible that excessive sleepiness could have similarly unpleasant effects. In one study, people who sleep too much were more likely to have a history of depression or drug addiction, and were strongly associated with unemployment and low socioeconomic status.

Myth 13: Going to bed early and waking up early makes you healthy, wealthy, and wise.

“Early to bed, early to rise, makes a man healthy, wealthy and wise . ” This quote was made famous by Benjamin Franklin, a scientist, polymath, and one of the founding fathers of the United States. The ancient Greek philosopher Aristotle was also a fan of early morning productivity, stating, “It is good to rise before dawn, for such habits contribute to health, wealth, and wisdom.”

But a study at the University of Liège concluded that these great thinkers have got the facts completely wrong.

When they compared early risers with late risers, they found that there was no significant difference in cognitive performance when the groups were tested in the morning. However, in the evening, early risers performed significantly worse on most tasks compared to their late risers.

Read: How to wake up early (and with an appetite) if you're not a morning person

Myth 14: Yawning is just a sign of tiredness

Yawning is commonly considered an indicator of fatigue, but in reality the causes of yawning remain a mystery even after constant scientific scrutiny.

One theory claims that yawning relieves low oxygen levels in the lungs, but this has been largely discredited after observations of fetal yawning (there is no oxygen in the womb).

Another mystery about yawning is the fact that it is extremely contagious. Studies have shown that yawning can trigger a contagious response in up to 60% of people exposed. It even affects dogs !

Some scientists have suggested that contagious yawning may have helped our ancestors coordinate times of activity and rest, while another recent experiment showed that yawning may be an attempt to cool the brain .

Myth 15: A warm glass of milk before bed helps you sleep

Some people believe that a glass of warm milk can help them fall asleep faster because it contains tryptophan, an essential amino acid responsible for producing serotonin, which is vital for healthy sleep.

However, evidence has shown that a glass of milk alone will not have these effects. Your body also needs foods rich in carbohydrates to help produce insulin.

This is necessary for tryptophan to have any sleep-inducing effects. It is possible that the effects of milk as a sleep aid may be purely psychological. People may associate milk with their childhood, maternal care, and sweet, childlike sleep.

Myth 16: Exercising before bed helps you sleep

Regular exercise has long been promoted as a vital part of a healthy lifestyle. Common sense tells us that when we are exhausted from physical exercise, we will feel tired and sleepy at the end of the day.

However, the relationship between sleep and exercise is more complex than many people realize. The current scientific literature investigating the effects of exercise on sleep is limited and inconsistent.

One study found that total sleep time decreased when participants exercised more. A different study concluded that there was no difference in sleep quality on non-exercise days and days of mild exercise.

Another sample of more than 2600 men and women found that 150 minutes of mild exercise per week provided a 65% improvement in sleep quality.

There's also conflicting advice about whether you should exercise in the morning, afternoon, or evening. However, don't let this confusion discourage you. The bottom line is that exercise is good for you.

Myth 17: If you can't sleep, count sheep

An old theory says that imagining images of sheep and counting them one by one can help you fall asleep. However, when scientists at the Department of Experimental Psychology at the University of Oxford tested it , they found the opposite was true.

Volunteers were asked to visualize a range of different scenarios as they tried to fall asleep. On average, those who visualized images of counting sheep took up to 20 minutes longer to fall asleep than those who imagined other scenarios, such as a relaxing beach.

Scientists have concluded that counting sheep is simply too repetitive and boring to occupy enough “cognitive space” in the brain. Essentially, this could lead to other distracting thought patterns entering your mind, making it harder for you to relax and ultimately fall asleep.

Tackle stress and insomnia with a gravity blanket

Gravity blankets are the most effective way to deal with insomnia and stress without medication, as they have been used for many decades to help people suffering from anxiety disorders, autism, and other sensory disorders.

How do they work?

They are designed to apply gentle, steady pressure to the entire body, which occupational therapists call “ Deep Tactile Pressure .” This steady pressure relaxes the nervous system and helps the body naturally increase levels of serotonin and melatonin (the hormones of happiness and sleep) while reducing levels of cortisol, which is responsible for stress.

As a result, the mind stops "racing", the heart rate drops, the mood improves and the body enters a state of complete relaxation.

Choose the one that weighs closest to 10% of your body weight and upgrade your sleep from the very first night.