Sleep sits right alongside food and water as a human life necessity. Adults need between 7 and 9 hours of quality sleep in a 24-hour period. But in a busy world, it’s tempting to treat sleep like it’s an option, and that can have devastating effects.
Sleep deprivation can lead to physical and mental health issues, injuries and increased chances of death. Yet, 33% of American adults report not getting adequate sleep and a staggering 40% report accidentally falling asleep during the day at least once a month.
The state of sleep
The rate of American adults getting sufficient sleep has declined from 72.3% in 2020 to 69.9% in 2022, leaving about one-third of adults facing their days without enough sleep. Philadelphia ranks as the worst city for sleep, while Austinites are well-rested and getting the best sleep of anyone in the country.
The sleep stages
There are four distinct stages of sleep, three non-rapid eye movement (NREM stages) and one rapid eye movement (REM stage). Most humans go through these stages of sleep between four and six times each night.
Despite more common talk of REM sleep, we spend approximately 75% of our sleep in an NREM stage. Only 5% of our sleep is spent in a light sleep stage.
MTStock Studio/Getty ImagesHumans cycle through two phases of sleep: rapid eye movement, or REM, and non-rapid eye movement, or NREM.
We cycle through the stages around four to six times each night, spending about 90 minutes in each cycle.
Approximately 75% of sleep is spent in an NREM stage.
Around 5% of sleep is spent in NREM stage 1, light sleep.
Around 45% of sleep is spent in NREM stage 2, deeper sleep.
Around 25% of sleep is spent in NREM stage 3, the deepest NREM sleep.
Around 25% of sleep is spent in REM, deep sleep.
Effects of sleep deprivation
It’s common to hear people joke about being sleep-deprived, but true sleep deprivation is no laughing matter. Nearly half of adults in the US report falling asleep accidentally during the day at least once a month. Since sleep is a visceral part of life, sleep deprivation can have devastating effects.
Sleep-deprived adults are significantly more likely to be overweight, which can also lead to other medical conditions. Those with insufficient sleep are also 2.5 times more likely to have diabetes, and 45% more likely to have a heart attack.
Almost 40% of adults fall asleep accidentally during the day at least once a month.
Adults aged 27 and above who sleep less than 6 hours in a day are 7.5 times more likely to have a higher body mass index.
Adults sleeping 5 hours or less are 2.5 times more likely to have diabetes.
There is a 45% increase in the risk of heart attack in adults sleeping 5 hours or less.
Common sleep disorders
If you’re living with a sleep disorder, you’re not alone. There are an estimated 50 to 70 million Americans currently suffering from a sleep disorder. Although there are over 90 known sleep disorders, some are much more prevalent than others. Insomnia affects approximately 1 in 3 adults, while only 1 to 5% are affected by a sleepwalking disorder. Sleep apnea is also common, creating poor sleep for 22 to 35% of adults, while only 2 to 7% of people have restless leg syndrome.
Though nightmares are commonly mislabeled as night terrors, true night terrors only impact around two percent of adults (but 37% of children).
An estimated 50 to 70 million Americans have a sleep disorder.
There are around 90 sleep disorders.
Insomnia is the most common sleep disorder, affecting about 1 in 3 adults.
Sleep apnea affects 22 to 35% of adults.
An estimated 1 to 5% of adults are affected by sleepwalking disorder.
About 2% of adults and 37% of children experience night terrors.
Approximately 5 to 10% of people are diagnosed with hypersomnolence disorder, which causes them to be excessively sleepy even when they get 7 or more hours of sleep.
Approximately 2 to 7% of people have symptoms of restless leg syndrome.
Maria Korneeva/Getty Images
Work-life balance and sleep
In the work-sleep discussion, we find ourselves asking how the cause and effect works out. Is work stress causing poor sleep, or is poor sleep causing work stress? The answer is both.
Employees who don’t get enough sleep are more likely (70%) to be involved in a workplace accident and also more likely to be in conflict with other employees. Insufficient sleep is also linked to a higher rate of absenteeism, and absenteeism can lead to getting behind on tasks and overwhelmed, creating more stress.
But poor sleep is also linked with decreased job satisfaction. In other words: Poor sleep can cause work problems, and work problems can cause poor sleep.
Insufficient sleep is linked to decreased job satisfaction.
Low sleep quality is tied to conflicts between leaders and their employees.
Employees who do not get enough sleep are 70% more likely to be involved in a workplace accident.
Insufficient sleep among employees results in more absenteeism, and an estimated $44.6 billion in lost productivity each year.
Age, gender and sleep
Before around three months of age, the sleep needs of newborns are generally the same, regardless of gender. But after that, we begin to develop circadian rhythms that start to affect when and how we sleep. As we develop into adults, there is a distinct difference in sleep patterns between men and women, and between adults and older adults.
Women tend to take longer to fall asleep than men but stay in slow-wave sleep longer than men. Men fall asleep faster and spend more time in the first stage of sleep known as light sleep. Then, men wake up more frequently during the night than women.
As we age, both males and females tend to wake around one and a half hours earlier and go to bed one hour earlier than they did as younger adults.
Men spend more time in the first stage of sleep than women.
Men experience more nighttime awakenings than women.
Women take longer to fall asleep but stay in slow-wave sleep longer than men.
Circadian rhythms develop around two to three months in newborns.
Teens spend less time in slow-wave sleep and more time in the second stage of sleep.
Older adults go to sleep around 1 hour earlier and wake 1.5 hours earlier than younger adults.
Mental health and sleep
Sleep and mental health are closely linked. Mental health is impacted by sleep, and sleep is impacted by mental health. Individuals with good or great mental health are six times more likely to get great sleep than individuals with fair or poor mental health. Nearly half of adults say sleep has a big impact on their mood.
A high-stress life nearly doubles a person’s chances of poor sleep. But then, worrying about sleeping increases your chances (three times) of not sleeping well. 81% of American adults say a racing mind or dealing with certain feelings impacts their sleep.
About 10 to 18% of the general population is affected by chronic sleep issues, compared to 50 to 80% of psychiatric patients.
Around 81% of Americans say their sleep is affected by their mind racing or feelings.
Adults who rate their mental health as excellent or very good are six times more likely to get good sleep than those who rate their mental health as fair or poor.
Stress nearly doubles the chances of poor sleep.
Worrying about not sleeping well makes you three times more likely not to sleep well.
Chronic sleep issues affect 50 to 80% of psychiatric patients, compared to 10 to 18% of the general population.
Almost half of adults (49%) say sleep has a major impact on their mood.
janiecbros/Getty Images
The impact of sleep aids
If you’re using prescription sleep aids to get some sleep, you’re in good company. Nearly half (46%) of people with sleep problems report using sleep aids. But 71% of adults are concerned about the safety of using sleep aids long term.
The most common prescription for sleep is Panadol, with over 49% of adults saying they take it. Another 39% say they use melatonin, an over-the-counter sleep aid.
Of people with sleep problems, 46% report using sleep aids.
Of American adults aged 20 and above, 4% say they use prescription sleep aids at least once a month.
Panadol is the most commonly used sleep aid, with over 49% of adults with sleep issues taking it.
Melatonin is also popular, with 39% of adults with sleep problems taking it.
But 71% of adults believe it is unsafe to use sleep aids in the long term.