Health Consequences of Sleeping Less Than 8 Hours Per Night in Adults

Optimal Sleep Duration

Most adults require 7-8 hours of sleep per night to maintain optimal health, though individual variation exists based on age, sex, genetic, and environmental factors 1, 3
Many "normal" sleepers overestimate their actual sleep duration, meaning populations believing they get adequate sleep may actually be chronically sleep deprived 1, 2

Short sleep duration (defined as <6 hours per 24-hour period) produces measurable deficits in cognition, vigilance, and memory 1, 3
Short sleep duration also affects mood and behavior 1
Ability to learn and general performance are impaired with short sleep duration 1
Immune function is also impacted by short sleep duration 1
Reaction time and perceived effort during tasks are affected by sleep deprivation, though physiological markers of anaerobic/aerobic power output may remain unchanged 4

Chronic insufficient sleep is associated with increased risk of diabetes mellitus 1, 2
Chronic insufficient sleep is also associated with increased risk of obesity 1, 2
Hypertension is another long-term consequence of chronic insufficient sleep 1, 2
All-cause mortality is increased with chronic insufficient sleep 1, 2

Insufficient sleep significantly increases risk of depression and anxiety 1, 4
Poor sleep predicts new onset of depression and anxiety disorders 4
Adults with sleep problems are more than twice as likely to experience overwhelming anxiety, severe depression, and suicidal ideation 4
Treating insomnia improves depression and anxiety symptoms 4

15-33% of fatal motor vehicle crashes may be due to drowsy driving 5, 6, 7
Those sleeping <6 hours per 24-hour period have markedly increased crash risk 5, 6
Increased risk of work-related injuries, particularly in shift workers and high-risk occupations 5, 6, 7
Adolescent athletes sleeping <8 hours are 1.7 times more likely to suffer musculoskeletal injuries 4

Older adults face increased fall risk when sleeping <7 hours per night 8, 9
Cognitive decline, difficulty with ambulation and balance are also consequences of insufficient sleep in older adults 8, 9
Increased mortality risk is associated with taking >30 minutes to fall asleep or having sleep efficiency <80% in older adults 8, 9
Decreased quality of life and increased symptoms of depression and anxiety are also seen in older adults with insufficient sleep 8, 9
Shift work is associated with obesity, insulin resistance, cardiometabolic issues, and cancer 5, 6, 7

Healthcare providers should screen for sleep duration routinely, recognizing that patients often overestimate their sleep duration 1, 2
Assessing for underlying sleep disorders and comorbidities that may contribute to insufficient sleep is crucial 2, 6
Educating patients about the importance of 7-8 hours of sleep in reducing chronic disease risk is essential 1, 2