What happens to the body when we sleep less than six hours?

Long-term sleep deprivation can seriously affect our lives.

A large number of scientific studies in recent years have shown that not getting enough sleep can lead to a number of diseases that are also life-threatening.

However, the world population seems to turn a deaf ear: two thirds of adults in all developed nations do not reach the recommended eight hours.

Approximately one in 4 million people are born with a gene that allows them to thrive on half that amount of sleep.

But for the vast majority, routinely sleeping less than six or seven hours a night destroys their immune systems and significantly increases their risk of developing numerous forms of cancer.

A study of 60,000 middle-aged and elderly Britons found that those who regularly needed naps during the day were 12 percent more likely to develop high blood pressure than their peers.

The researchers concluded that naps themselves were not the problem and suggested that they were a sign of poor quality nighttime sleep.

Sleep deprivation also increases the risk of coronary arteries becoming blocked and brittle, leading to the development of cardiovascular disease, stroke, or heart failure.

Sleep disruption can also contribute to major psychiatric conditions such as depression and anxiety. Sleep deprivation has even been linked to suicide.


Routinely not getting enough sleep has been linked to increased “wear and tear” on our cells. This type of action on our genes is believed to give rise to cancerous tumors.

A 2019 study found that people who work night shifts have 30% more DNA damage than those who work normal hours.

Heart problems

The link between an unhealthy sleep pattern and a “sick” heart is becoming undeniable. As we approach middle age, and our bodies and health begin to deteriorate, the impact of lack of sleep on the cardiovascular system increases.

Adults 45 and older who sleep less than six hours a night are 200% more likely to have a heart attack or stroke during their lifetime, compared to those who sleep seven to eight hours a night.


A growing body of scientific evidence shows that not getting enough sleep in midlife is linked to dementia in later life. It is believed that when we don’t get enough sleep, we don’t give the brain time to drain amyloid beta and other plaques.

This allows the substances to continue to accumulate, day after day, until they cause the memory-robbing disorder.


The short duration of sleep can lead to obesity through an increase in appetite through hormonal changes caused by lack of sleep, since it produces ghrelin, a hormone that, among other effects, stimulates appetite.

Sleep deprivation is also associated with growth hormone deficiency and elevated cortisol levels, both of which have been linked to obesity.

weakened immunity

Research has even shown that people who sleep little are less likely to get a full immune response from vaccinations.

Researchers have also found, in a 2012 study, that people who sleep less than six hours a night are, on average, much less likely to mount an antibody response to the hepatitis B vaccine.


Research shows that poor or insufficient deep sleep has a dramatic effect on the body’s metabolism and the conversion of sugar to energy, increasing the risk of diabetes.

Just three nights of interrupted sleep can have the same effect on your body’s ability to control blood sugar levels as gaining five pounds or more and being in a pre-diabetic state.

low sexual desire

Not getting enough sleep at night can kill the sex drive in men. A 2011 University of Chicago study found that those who sleep less than five hours a night, for periods longer than a week, have significantly lower testosterone levels than those who rest all night.

And since testosterone affects men’s libido and energy levels, those who don’t sleep are much less likely to feel like having sex.

The effect is so drastic that it reduces the hormone to levels similar to those of someone 15 years older, as reported in the Journal of the American Medical Association.