Sleep: how much do adults need and why it matters for health

Updated November 14, 2026 Well Day Media Editorial Team

A woman sleeping peacefully in a tidy, dark bedroom

The short answerAdults need at least 7 hours of sleep on a regular basis; for most people aged 26 to 64, 7 to 9 hours is ideal. Short sleep is linked to higher risk of death and chronic disease. For chronic insomnia, the most effective first step is cognitive behavioral therapy for insomnia (CBT-I), not sleeping pills.

Key points

AASM and Sleep Research Society: adults should sleep 7 or more hours per night on a regular basis.
National Sleep Foundation: 7 to 9 hours for ages 18 to 64, 7 to 8 hours for 65 and older.
Meta-analysis: short sleep was linked to 12% higher mortality and very long sleep to 30% higher (likely as a marker of illness).
CBT-I improves time to fall asleep and sleep quality and is recommended as first-line treatment for chronic insomnia.

Why we need sleep

During sleep, the brain processes and consolidates information, the body repairs itself, and appetite hormones, blood sugar and immunity are regulated. Lack of sleep worsens mood, concentration and reaction time, and over the long run it is linked to heart disease, type 2 diabetes, obesity and depression. The CDC estimates that about one in three U.S. adults does not get enough sleep.

How much to sleep: the expert consensus

The American Academy of Sleep Medicine and the Sleep Research Society carried out a systematic review of the literature and a consensus vote. Their conclusion: adults should sleep 7 or more hours per night on a regular basis, and less than 7 hours is associated with adverse health outcomes (Watson et al., 2015).

The National Sleep Foundation issued recommendations by age (Hirshkowitz et al., 2015):

Age	Recommended
14–17 years	8–10 hours
18–25 years	7–9 hours
26–64 years	7–9 hours
65+ years	7–8 hours

Short and long sleep

A meta-analysis of prospective studies covering more than 1.3 million people found that short sleep was linked to a 12% higher risk of death, and long sleep (usually more than 8 to 9 hours) to a 30% higher risk (Cappuccio et al., 2010). The authors stress that long sleep probably does not cause harm by itself but is a marker of hidden illness or depression.

Quality matters as much as quantity

Signs of good sleep:

you fall asleep within about 30 minutes;
you wake up no more than once a night, or fall back asleep quickly;
you feel rested in the morning;
you do not struggle with overwhelming daytime sleepiness.

If sleep will not come: what works

For chronic insomnia, the best-studied non-drug treatment is cognitive behavioral therapy for insomnia (CBT-I). It combines a regular schedule, limiting time in bed, working with the thoughts that keep you awake and relaxation training. A meta-analysis of randomized trials found that CBT-I shortened the time to fall asleep by about 19 minutes, reduced time awake after falling asleep by about 26 minutes and improved sleep efficiency (Trauer et al., 2015). Unlike sleeping pills, the benefits last after treatment ends. The American College of Physicians recommends CBT-I as the first-line treatment for chronic insomnia.

Core habits for healthy sleep

Go to bed and get up at about the same time, even on weekends.
Get daylight in the morning and less bright screen light in the evening.
Limit caffeine in the afternoon.
Avoid alcohol before bed: it worsens sleep quality.
Keep your bedroom dark, quiet and cool.

Elsewhere in this section: bedtime routines, caffeine and sleep, and sleeping through anxious times.

Frequently asked questions

How many hours of sleep does an adult need?

At least 7 hours on a regular basis. The recommended range is 7 to 9 hours for ages 18 to 64 and 7 to 8 hours for 65 and older.

Can I catch up on sleep on weekends?

Extra weekend sleep partly makes up for a sleep debt, but big shifts in your schedule disrupt your body clock. It is better to keep a similar wake-up time every day.

Is sleeping more than 9 hours harmful?

Long sleep is linked to higher mortality in studies, but probably because it is often a sign of illness, depression or poor-quality sleep. If you regularly sleep long and still do not feel rested, talk to your doctor.

Sources

Watson et al. (2015). Recommended Amount of Sleep for a Healthy Adult: A Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society. SLEEP. doi:10.5665/sleep.4716
Hirshkowitz et al. (2015). National Sleep Foundation’s sleep time duration recommendations: methodology and results summary. Sleep Health 1(1):40-43. doi:10.1016/j.sleh.2014.12.010
Cappuccio et al. (2010). Sleep Duration and All-Cause Mortality: A Systematic Review and Meta-Analysis of Prospective Studies. Sleep 33(5):585-592. doi:10.1093/sleep/33.5.585
Trauer et al. (2015). Cognitive Behavioral Therapy for Chronic Insomnia. Annals of Internal Medicine 163(3):191-204. doi:10.7326/M14-2841

Prepared according to our evidence methodology and the principles of lifestyle medicine. For education only; it does not replace advice from your doctor.

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Sleep: how much do adults need and why it matters for health

Key points

Why we need sleep

How much to sleep: the expert consensus

Short and long sleep

Quality matters as much as quantity

If sleep will not come: what works

Core habits for healthy sleep

Frequently asked questions

Sources

Keep reading

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Sleeping through stressful times: how to recover when nights are restless

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