Balancing work, a social life and staying fit and healthy can mean a good night’s sleep is often sacrificed.
But a lack of shut-eye can trigger wide-ranging and severe health problems, beyond just feeling a little tired.
This is because snoozing is vital for healing the heart and blood vessels, while those who are extremely sleep deprived are even at risk of damaging their organs.
Here, MailOnline reveals the five signs you’re not getting enough sleep, according to retailer Bed Kingdom.
The warning signs that you’re not getting enough sleep include craving a takeaway, having poor memory, overheating, weight gain and making poor decisions
Craving a takeaway
If you’re getting sudden urges to indulge in a takeaway or junk food, it could be a sign you’re sleep deprived.
A lack of sleep alters appetite-regulating hormones, according to scientists from the University of California.
The small 2014 study monitored the food cravings of 23 healthy participants on nights where they had normal sleep and nights of total sleep deprivation.
They found that, when volunteers did not get enough sleep, participants were more likely to turn to junk food. The researchers believe this was due to cravings for high calories, high sugar and high fat snacks as a way to increase energy levels.
But researchers from Northwestern University Feinberg School of Medicine found in 2019 that the cravings for unhealthy food among those who don’t sleep enough could be down to your nose, or olfactory system — the sense of smell.
Experts suggest that when you are sleep deprived, your nose is too tired to signal enough information to the brain regarding different food odours.
This can result in you reaching for richer food with a stronger odour, often junk food.
Many people may feel more forgetful when they are tired.
This is because sleep deprivation affects the brain’s ability to learn and recall information.
During rapid eye movement sleep (REM), which is known for dreaming, the brain is active, building and storing memories from the previous day, according to the Sleep Foundation.
Less sleep disrupts this process, interrupting the formation of memories and absorbing of information.
And people who are sleep deprived are even at risk of forming false memories, according a study of 60 people by medics in Singapore, published in the Journal of Sleep Research in 2016.
Not only is your ability to remember affected by a lack of shut-eye, sleep is also essential for reinforcing the learning and absorbing of motor skills and physical reflexes – hence the term muscle memory.
This is another reason why a high percentage of car accidents occur due to sleep deprivation, as experts say sleep-deprived drivers have a slower reaction time.
A lack of sleep could even hamper attempts at losing weight.
Sleep duration has long been linked to the body’s production of appetite-regulating hormones, according to Harvard University researchers.
They say insufficient sleep is associated with higher levels of the hormone ghrelin, which increases appetite and signals hunger.
Sleep deprivation is also linked with lower levels of the hormone leptin, which is needed to feel full.
As a result, higher levels of ghrelin coupled with less leptin will leave you feeling hungrier and your body will be slower to react when you’re full — increasing the risk of overeating.
Sleep deprivation also increases stress, which causes an increase in cortisol levels.
Cortisol is a stress hormone responsible for holding onto energy (sugars and fat) to be used later. So higher levels of this hormone means your body retains more fat.
How much sleep do people need?
How much sleep you need each night to avoid being sleep deprived depends on how old you are.
Newborns (0 to 3 months) need between 14 and 17 hours of sleep.
Infants (4 to 11 months) need between 12 and 15 hours of sleep.
Toddlers (1 to 2 years) need between 11 to 14 hours of sleep.
Children aged 3 to 5 need 10 to 13 hours of sleep.
Children aged 6 to 12 years need 9 to 12 hours of sleep.
Teenagers (13 to 18 years) need 8 to 10 hours of sleep.
Adults aged 18 to 60 need 7 or more hours of sleep.
Adults aged 61 to 64 need 7 to 9 hours of sleep.
Adults aged 65 or over need 7 to 8 hours of sleep.
Source: Centers for Disease Control and Prevention (CDC)
Experts say insulin levels are also affected by too little sleep, as higher levels of cortisol leaves the body less sensitive to insulin.
Insulin is a hormone that changes food into energy. The body has a harder time processing fats from the bloodstream when it becomes less sensitive to insulin.
Over time, this leads to fat storing up in the body and weight gain.
Poor decision making
Studies show that sleep loss is tied to making risky decisions.
In 2020, scientists in Italy looked at the effects of total and partial sleep deprivation on a person’s risk taking and impulsivity.
They studied 74 people — 32 of whom had one night of however many hours of sleep was regular for them (they all said they usually get 7-8 hours), followed by a night of no sleep at all, arriving at a laboratory at 9pm and staying completely awake all night.
The rest of the people, 42, had five nights of regular sleep, according to their own sleep habits, followed by five nights of partial sleep deprivation – where they had to go to sleep at 2am and wake up at 7am.
They found that those who had prolonged sleep deprivation, albeit partial, suffered more detrimental results.
For the study published in the Nature of Science and Sleep journal, the authors wrote: ‘Under the effects of sleep loss, people [who are] habitually more reflective and cautious become more impulsive and prone to risk-taking during decision-making based on deliberative reasoning.’
Experts have suggested this increase in risk-taking when sleep deprived is due to an decreased function of the prefrontal cortex — the part of the brain that regulates thoughts, actions and emotions.
Sleep is vital for the body to regulate our internal temperature, experts say.
Without sleep, it struggles to maintain the normal 37C (98.6F) temperature.
This means as people get more tired, their brains could be getting hotter, according to Boston University scientists.
Yawning — a tell-tale sign of tiredness — is a method of compensating for this thermoregulatory failure and helps cool down the brain, they say.
So the next time you feel hot and bothered, it could be a sign that you need some more sleep.