If the average night's sleep is eight hours (ie one third of a day), one sleeps for one third of one's life. If you live, say, 75 years, that's 25 years asleep, or 9,125 days.
1. Sleeping. A good night's sleep is vital for every human being to survive. Given that an average a person sleeps for 8 hours in a day, that means that an average person will sleep for 229,961 hours in their lifetime or basically one third of their life.
While the world average sleep duration is just over 7 hours, the average at country level varies by almost an hour. Of the 63 nationalities researched, Albanians were the longest sleepers, averaging 7 hours and 32 minutes per night.
Editor's note: Kleine-Levin Syndrome mostly affects teen boys, causing them to sleep up to 20 hours a day during episodes that can last weeks. It's rare, possibly affecting one person in a million, with a higher incidence among Jewish people.
Sleep and Aging
Older adults need about the same amount of sleep as all adults—7 to 9 hours each night. But, older people tend to go to sleep earlier and get up earlier than they did when they were younger. There are many reasons why older people may not get enough sleep at night.
While most adults need between seven and nine hours of sleep, some adults average five or fewer hours of sleep each night. While it may seem like enough sleep, regularly getting only five hours of sleep each night may lead to sleep deprivation.
adults (26–64 years): 7–9 hours. older adults (65 years and above): 7–8 hours.
Hypersomnia means excessive sleepiness. There are many different causes, the most common in our society being inadequate sleep. This may be due to shiftwork, family demands (such as a new baby), study or social life. Other causes include sleep disorders, medication, and medical and psychiatric illnesses.
Oversleeping, or long sleeping, is defined as sleeping more than nine hours. View Source in a 24-hour period. Hypersomnia. View Source describes a condition in which you both oversleep and experience excessive sleepiness during the day.
The average Aussie goes to bed just after 10:45pm, which is more than an hour earlier than the late night Spaniards, the University of Michigan's global sleep pattern research found. As well as the early nights, Australians are the first to rise along with Americans who both get up just after 6:45am.
According to a 2021 survey by the Organization for Economic Cooperation and Development (OECD), Japanese sleep an average of seven hours and 22 minutes. This is the shortest duration among the member countries and almost an hour less than the OECD average of 8 hours and 24 minutes.
Unfortunately, most people cannot have a healthy lifestyle with only four hours of sleep, research suggests. However, personal and anecdotal evidence supporting shorter sleep by using polyphasic sleep suggests otherwise. This means that we cannot say for sure if you can thrive on four hours of sleep.
“While consistently getting less than the recommended amount of sleep has been associated with multiple adverse health outcomes, sleeping more than nine hours per night regularly may also be detrimental,” Makekau says. She says oversleeping can lead to: Increased fatigue and low energy. Decrease in immune function.
A person with an 8-hour sleep need who gets 6 hours each day for 5 days builds a sleep debt of 10 hours. As sleep debt builds, brain and body functioning deteriorate. Sleep is needed to “pay down” this debt.
It's the body's way of recharging and healing. For some people, it's also a great escape. Dreaming is fun, and sleep is a way to get away from problems in the real world. Sleep enthusiasts know that a good snooze is a great cure for things like stress, anxiety, and a bad mood.
Sleeping a lot isn't necessarily a bad thing. Sleep is important. Not getting enough sleep puts you at risk for health problems, from heart disease to obesity to diabetes. However, sleeping a lot all of a sudden when you didn't before might be a reason to look closely at what is going on with your health.
Most likely, you're still tired after 8 hours of sleep because you don't know your sleep need, you're getting less sleep than you think, you've got sleep debt, or you're out of sync with your circadian rhythm.
If you aren't feeling rested when you wake up, despite getting to sleep at least 8 hours prior, then it might not be the quantity of your sleep that's the problem. It could be your sleep quality that needs some attention. The amount of sleep you get is important, but equally important is the quality of that sleep.
“Women are also multi-taskers, and they do a lot at once. Because they use more of their actual brain, they may need a little bit more sleep than men. It is still debatable, but some experts say that women need twenty more minutes on average than men usually need.”
“There is no such thing as a “fixed or ideal time” to go to bed which will suit all individuals. It is generally advisable to fall asleep between 10 pm to midnight as for most people this is when the circadian rhythm is at a point that favours falling asleep.”