In 2015, the American Academy of Sleep Medicine and the Sleep Research Society published a joint consensus recommending that adults should sleep seven to eight hours per night on a regular basis to promote optimal health.
Before the broad usage of the light bulb in early 1900, people used to sleep nine hours on average. Current surveys indicate that 35–40 percent of the adult US population report sleeping less than the usually recommended seven to eight hours on weekday nights and about 15 percent report sleeping fewer than six hours.
Sleep deprivation can be caused by sleep disorders, work schedules, and modern lifestyles. When we do not get enough sleep, or when we have poor quality sleep, we feel very tired throughout the day. Sleep deficiency can interfere with work, school, driving, and social functioning. You might have trouble learning, focusing, and reacting. Also, you might find it hard to judge other people’s emotions and reactions. Sleep deficiency also can make you feel frustrated, cranky, or worried in social situations. Sleep deprivation also appears to play a role in chronic health diseases, such as dementia, cardiovascular disease, obesity, and type 2 diabetes.