While some people regularly function on short periods of sleep, research mostly agrees that six hours of sleep is not enough for most adults. Experts recommend that most adults need at least seven hours of sleep every night.
Five hours of sleep most likely isn't enough to feel and function your best. Most of us need seven and a half to nine hours of sleep, and some of us may need even more.
Additional studies are needed to determine if setting your alarm clock earlier will actually improve your health. [But] individuals who now average 6.5 hours of sleep a night can be reassured that this is a safe amount of sleep. From a health standpoint, there is no reason to sleep longer."
According to the Center for Disease Control and Prevention, teenagers need 8-10 hours of sleep, while adults 18-60 need 7 hours in a 24-hour period.
But sleeping for 6 hours per night may not necessarily feel like deprivation, especially if you find that you wake up feeling rested. Yet, sleep journals and public health officials almost universally recommend getting eight hours of sleep a night, and if not that, then at least seven hours.
Compared with those who got between six and eight hours sleep a night, those who slept for less than six hours had an 11% greater risk of heart disease or stoke; and those who slept for more than eight hours a night had a 33% greater risk.
So why do people think they are able to function optimally on 6 hours of regular sleep? This is because of a natural human phenomenon known as 'renorming'. Renorming means that we are only able to compare how we feel today to how we felt yesterday or the day before.
The bare minimum of sleep needed to live, not just thrive, is 4 hours per 24-hour period. Seven to 9 hours of sleep are needed for health, renewal, learning, and memory. Disruption of the sleep cycle from shift work creates problems for the quality and quantity of sleep.
This is because our brain is constantly forming new connections while we are awake. The longer we are awake, the more active our minds become. Scientists believe that this is partly why sleep deprivation has been shown to reduce symptoms of depression.
Getting only six hours of sleep each night is considered a poor sleep schedule that can result in sleep deprivation and lead to poor mental health and potential sleep disorders. You can survive on six hours of sleep but that would not be good for your long-term health.
Try an afternoon nap: While napping is not a replacement for lost sleep, it can help you feel more rested during the day. Naps may be particularly helpful for shift workers or people who have trouble maintaining a consistent sleep schedule. Even a short power nap can refresh the body and brain.
To date, there are no known health problems related to being a true short sleeper. In contrast, studies have found people with insomnia or those who intentionally restrict their sleep to less than six hours per night despite requiring more sleep have a higher risk of numerous health problems, such as heart attacks.
“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.”
Not everyone needs the same amount of sleep, but on average adults need between 7-9 hours of sleep each day. Babies and young children need much more sleep, but from young adulthood sleep needs remain relatively stable.
Chronic sleep debt is the sleep debt that builds up over months or years. For example, if you need nine hours of sleep, but you've spent your whole adult life only getting six or seven hours of shut-eye, you'll have some serious chronic sleep debt.
Chronic sleep deprivation is defined as a curtailed sleep that persists for three months or longer. Chronic sleep deficiency or insufficient sleep can describe ongoing sleep deprivation as well as poor sleep that occurs because of sleep fragmentation or other disruptions.
Signs and symptoms of sleep deprivation
Feel tired, irritable, and fatigued during the day; yawn frequently. Have difficulty focusing or remembering things. Feel less interested in sex. Find it difficult to get out of bed in the morning, need an alarm clock to wake up on time, or repeatedly hit the snooze button.