Do you know someone, or are you yourself someone, that claims they can run on five or six hours of sleep and be just fine? While you may feel okay, the reality is is that getting sufficient amount of sleep requires you to sleep for much longer than five or six hours. Although you may be able to function in the long-term, or your body has adapted to that after years of building that habit, that doesn't mean that you aren't suffering to some degree. Continue reading to find out what happens to your body when you get different amounts of sleep. 

Your Body on Eight Hours of Sleep

Eight hours of sleep has been supportive as the right amount of sleep. An experiment done by Nathaniel Kleitman in 1938 showed that eight hours is the body's prefered time when he spent 32 days in a dark cave to see how the body responded to a lack of sunlight. 

Eight hours of sleep was further supported by a huge sleep study completed in 2018 by the University of Western Ontario. They compared 10,000 participants who received varying levels of sleep. Researchers looked at performance on cognitive exercises after participants received equal to, more, or less than eight hours of sleep. They found that those who received eight hours performed better than everyone else. 

Getting enough sleep also reduces the effects of sleep deprivation, including a lack of emotional intelligence and poor working memory. 

Your Body on Six of Hours

When you achieve less than eight hours of sleep, quick thinking and reflexes are among the first of your skills to go. In an experiment in which participants but click a number that pops up on the screen as soon as they see it, researchers saw that those who received less sleep were very lethargic, with everything requiring more effort. 

Another study where individuals were told to sleep varying amounts saw that participants who only received six hours of sleep saw a decline in their cognitive functions, their alertness, ability to reason, communication and memory. These ability slowly decline with each subsequent day of sleep deprivation. By the sixth day, these participants were falling asleep during certain asks. By the end of the two-week trial, they were performing just as poorly on cognitive tests than those who had been sleep deprived for an entire night straight. 

Outside of a study, receiving only six hours of sleep a night on a regular basis can put you at risk for physical danger. Your increased risk for a car crash is 33%, compared to those who sleep 7-8 hours. 

Your metabolism can also take a hit when you only get six hours of sleep a night. Those with an average of 5-6 hours of sleep a night start to develop a blood glucose tolerance level where they begin to enter prediabetic rangers. This is because they have increased amounts of the hormone, cortisol, which is associated with increased insulin resistance. Poor sleep can put you at risk for both weight gain and associated health consequences, such as heart disease. 

A recently published study also just found that reduced sleep makes you more selfish. There was a 10% decrease in online charitable donations across the whole U.S. population in the weeks after Daylights Savings, which caused people to get one less hour of sleep for only one night. Also, this study showed that people who experienced sleep deprivation across several nights were less likely to help other people during an altruism test. 

Your Body of Four Hours of Sleep 

Participants who slept for only four hours in a study were significantly worse than those who slept for six hours. After three days, they responded as if they had gone a whole night without sleeping, based on their cognitive test results. By the tenth day, they were performing as if they had been up for 48 hours, or two days, straight. 

This study demonstrated that the less sleep you achieve, the less number of days you are going to be able to continue sleeping like that without severe consequences. 

The other interesting finding in the study was that those who had low levels of sleep did not realize that sleep was the reason for their inability to score well on the cognitive exams. They attributed it to other reasons, showing the lack of awareness people have about the impact of sleep and sleep deprivation. They felt tired, but didn't think that had anything to do with their reports. 

The longer individuals limited themselves to four hours, the worse their outcomes. The 10,000 participant study found that people who only had four hours of sleep aged their brain by about 8-9 years as compared to those who were regularly getting eight hours of sleep. 

There are also physical consequences, which immunosuppression and immunocompromised resulting from a lack of sleep. These changes are often irreversible after a certain amount of time with little sleep, as well. So it's important to recognize the impact of sleep deprivation early, because the consequences can be unforgiving. 

Your Body on Two Hours of Sleep

Functioning on two hours of sleep is just not possible, especially when trying to sustain it over a long period of time. Sleeping this little can actually have some detrimental consequences. Sleeping in the hospital is a great example of this, as the hospital comes with a lot of disruptions, and those who are in the hospital often fare worse because of these interruptions. Circadian rhythms are completely perturbed, especially in the ICU, when they are constantly being checked on. Eventually, this can lead to ICU psychosis where patients begin to experience paranoia and hallucinations. 

However, any little amount of sleep is still better than no sleep. Sleep phases last 90 minutes, so if you sleep for at least two hours, then you can make it through one sleep cycle. This is significantly better than just receiving an hour of sleep. 

You Body on Zero Hours of Sleep 

It's unfortunate, but sometimes pulling an all-nighter is a necessity. It is not the end of the world, but it is not without its consequences either. 

A study published in 2014 showed that being sleep deprived for one night can lead to an increased emotional response and negative feelings by about 60%. CDC research shows that being awake for 18 hours can cause the same confusion and impairment as being a little drunk, or a blood-alcohol level of 0.05%. Going a full 24 hours without sleep is the same has having a blood alcohol level of 0.10% 

There is no record of someone dying from sleep deprivation, but trying to beat the world record for staying awake (264 hours, or 11 days) is probably not the best idea either. 

If you are having trouble sleeping, and find that you often fall into one of the categories other than eight hours, then please click the orange button and take a free online sleep test to talk to one of our sleep health professionals. 

https://www.theguardian.com/lifeandstyle/2022/sep/24/want-to-get-a-good-nights-sleep-first-of-all-stop-trying