According to numerous studies, adults need an average of seven to nine hours of sleep each night. However, the reality is that many people sleep much less than that.
A 2023 study even found that getting less than six hours of sleep a night can reduce the body's immune response to vaccines. In addition, chronic sleep deprivation can have numerous consequences for your body.
While we sleep, our bodies work hard to fight infection. Dr. Sue Peacock, a consultant health psychologist and sleep expert, told the British newspaper Metro: "Research shows that there is a complex relationship between our sleep-wake cycle and our immune system."
While you sleep, your immune system produces protective substances that fight infection, such as cytokines. It uses these substances to fight foreign invaders like bacteria and viruses.
"These cytokines also help you sleep, giving your immune system more energy to protect the body from disease. This reduces the body's response to infection," she added.
So if you don't get enough sleep, you don't produce enough of these magical cytokines. This increases our susceptibility to illness and it can take longer for you to recover from illness.
A 2023 study also found that getting less than six hours of sleep a night reduces our immune response to vaccines. Researchers at the French National Institute of Health reanalyzed the results of seven studies that compared antibody responses in people who slept seven to nine hours a night versus those who slept less than six hours.
Unfortunately, sleep and anxiety can be a bit of a viscous cycle. Lack of sleep causes anxiety, but anxiety can also cause lack of sleep.
Dr. Sue says, "Unfortunately, one can make the other worse. Furthermore, anticipatory anxiety and sleep-specific anxiety can lead to sleep disorders and insomnia, which then create a feedback loop that can make both conditions worse."
Anxiety can negatively impact your body's ability to sleep, as your brain is in "fight or flight" mode, thinking about all the possible outcomes of whatever is causing the anxiety.
Research has also found that lack of sleep can make us feel sad. This can lead to a reduced ability to stay positive when faced with emotionally challenging events, says Dr. Sue.
"You may also feel less able to enjoy positive experiences," he says.
Lack of sleep can also disrupt thyroid hormones, causing problems for women who are menstruating.
Dr. Katharina Lederle, a sleep and biological clock specialist, said: "Thyroid-stimulating hormone (TSH) levels increase during sleep deprivation, and in healthy young women in the follicular phase, this is associated with a significant increase in TSH levels."
High TSH levels cause menstrual irregularities, anovulation (when an egg is not released), amenorrhea (when you don't get your menstrual cycle), and recurrent miscarriages.
Have you ever wondered why you feel hungry after a bad night's sleep? While we sleep, hormones like cortisol, leptin, and ghrelin are regulated - hormones that are important for weight control.
Lack of sleep lowers the levels of these hormones in the blood, so long-term sleep deprivation increases appetite, overeating, and weight gain. Obesity is also more likely in those who don't sleep well.
If you don't get enough sleep, you're much less productive during the day. A US study found that employees who slept an average of five hours a night missed 2.22 workdays per year, compared to 1.48 days for those who slept eight hours.
Lack of sleep negatively impacts all the things we need to do well at work: cognitive performance, decision-making, memory, and attention span.
Research shows that people who sleep less are at greater risk for cardiovascular diseases, such as hypertension, stroke, and heart attack. There is also an increased risk for diabetes and other chronic diseases.
Not only that, but lack of sleep is also linked to impaired memory and cognitive function - even increasing the risk of Alzheimer's disease.
