How Much Sleep Do Adults Really Need?
"Eight hours" is the number everyone knows. The expert consensus is a range, not a single figure, and the regularity and quality of sleep matter almost as much as its length.
What the expert bodies recommend
| Source | Adults | Older adults |
|---|---|---|
| American Academy of Sleep Medicine and Sleep Research Society (2015 consensus) | 7 hours or more per night, on a regular basis, for ages 18–60 | — |
| US Centers for Disease Control and Prevention | 7 or more hours (18–60); 7–9 hours (61–64) | 7–8 hours (65+) |
| National Sleep Foundation (2015) | 7–9 hours (18–64) | 7–8 hours (65+) |
| NHS | Most adults need between 6 and 9 hours | — |
Teenagers need more: the AASM recommends 8 to 10 hours for ages 13 to 18, and younger children more still. The AASM consensus panel also noted that sleeping more than 9 hours regularly may be appropriate for young adults, people recovering from sleep debt and people who are ill, but that for others it can be a sign of an underlying problem worth discussing with a doctor.
These recommendations are based on reviews linking short sleep with poorer health outcomes. Regularly sleeping less than 7 hours is associated with weight gain, high blood pressure, type 2 diabetes, heart disease, depression, impaired immune function, more errors and a greater risk of accidents. Most of this evidence is observational: it shows associations, and short sleep is often tangled up with stress, shift work, illness and other factors. Experimental studies of sleep restriction do, however, show clear short-term effects on attention, mood and glucose regulation.
How many people fall short
The CDC reported that about a third of US adults (35%) said they usually slept less than 7 hours in a 24-hour period, based on a 2014 national survey. Shift workers, parents of young children and people with long commutes or multiple jobs are particularly affected.
Signs you may not be getting enough
- needing an alarm and feeling unrefreshed most mornings;
- sleeping much longer on free days than on work days;
- falling asleep within minutes of lying down at any time of day, or dozing off when reading, watching TV or as a passenger;
- irritability, low mood, poor concentration or memory lapses;
- relying on caffeine to get through the day.
Feeling sleepy while driving is dangerous. If you start to feel drowsy at the wheel, stop somewhere safe and rest.
Quality and regularity matter too
Time in bed is not the same as sleep. Fragmented sleep (frequent waking) leaves people tired even after a long night. Researchers have increasingly studied sleep regularity, meaning going to bed and waking at similar times each day; irregular schedules are associated with poorer health in observational studies, and a consistent wake time helps keep the body clock stable. See daylight and your body clock.
Habits with evidence behind them
Advice often called "sleep hygiene" is a sensible starting point, though on its own it is rarely enough to treat chronic insomnia. Points with reasonable support include:
- Keep a regular wake time, including at weekends where possible.
- Get daylight in the morning and keep evenings dimmer.
- Watch caffeine timing. Caffeine's half-life averages around five hours in adults, with wide individual variation, so an afternoon coffee can still be active at bedtime. EFSA considers up to 400 mg a day safe for most adults (200 mg in pregnancy), but sleep can be affected at lower amounts, especially later in the day.
- Be wary of alcohol as a sleep aid. It can help people fall asleep but disrupts sleep later in the night.
- Keep the bedroom dark, quiet and cool enough to be comfortable.
- Be active during the day. Regular physical activity is associated with better sleep quality.
- Avoid lying in bed for long periods awake. If you cannot sleep, getting up and doing something calm in dim light until sleepy is part of standard behavioural treatment.
Insomnia and when to see a doctor
Insomnia means difficulty getting to sleep, staying asleep or waking too early, despite the opportunity to sleep, with daytime effects. When it happens at least three nights a week for three months or more, it is considered chronic. Guidelines from the American College of Physicians (2016) and NICE recommend cognitive behavioural therapy for insomnia (CBT-I) as the first-line treatment for chronic insomnia in adults. CBT-I includes sleep scheduling, stimulus control and work on unhelpful thoughts about sleep, and is available in person and through approved digital programmes in some health systems.
Sleeping pills are generally intended for short-term use because of side effects and dependence risks. Melatonin is prescription-only in the UK and sold as a supplement in the US; the AASM's 2017 guideline suggested not using melatonin to treat chronic insomnia in adults because evidence of benefit was weak.
See a doctor if you have long-standing sleep problems, if a partner notices loud snoring with pauses in breathing or gasping (possible obstructive sleep apnoea), if you are very sleepy during the day despite enough time in bed, or if you have unusual movements or behaviours in sleep. Sleep apnoea is common, often undiagnosed and treatable.
In short
- Most adults need at least 7 hours a night on a regular basis; 7 to 9 hours is the commonly cited range.
- Older adults typically need 7 to 8 hours; teenagers 8 to 10.
- Regular timing and uninterrupted sleep matter, not just total hours.
- Chronic insomnia is best treated with CBT-I; loud snoring with pauses in breathing deserves a medical check.
This page is general information, not medical advice. If poor sleep affects your daily life, talk to a doctor.
Sources
- Watson NF et al. Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. Sleep 2015;38(6):843–844.
- US Centers for Disease Control and Prevention, About sleep.
- Hirshkowitz M et al. National Sleep Foundation's sleep time duration recommendations. Sleep Health 2015;1(1):40–43.
- NHS, Insomnia.
- Qaseem A et al. Management of chronic insomnia disorder in adults: a clinical practice guideline from the American College of Physicians. Ann Intern Med 2016;165(2):125–133.
- EFSA, Caffeine.
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