A pillar of lifestyle medicine
Sleep
How much to sleep, how to fall asleep more easily and why sleep underpins physical and mental health. It is one of the six pillars of lifestyle medicine: restorative sleep.
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Guide
Sleep: how much do adults need and why it matters for health
How much sleep adults need according to sleep medicine experts, how short and very long sleep are linked to health and what works for insomnia.
All articles
Sleep A bedtime routine for better sleep: what really helps
Which sleep hygiene habits are backed by research, why screens delay sleep, a 60-minute wind-down routine and when a routine alone is not enough.
Sleep Caffeine and sleep: how many hours before bed to stop
How much caffeine shortens and lightens sleep, the cutoff time recommended by a 2023 meta-analysis and how much caffeine is in common drinks.
Sleep Sleeping through stressful times: how to recover when nights are restless
How stress, emergencies and anxious news cycles disrupt sleep, and habits that help you recover: a steady wake time, daylight, limiting news and relaxation.
Sleep Insomnia: what CBT-I is and why it is first-line treatment
What cognitive behavioral therapy for insomnia involves, why U.S. and European guidelines recommend it before sleeping pills and where to find it.
Sleep Napping: how long to nap for real benefits
Why a 10- to 20-minute nap boosts alertness without grogginess, what experiments show about nap length and the best time of day to nap.
Sleep Snoring and sleep apnea: when it is dangerous
What obstructive sleep apnea is, how common it is, the STOP warning signs and the treatments that work, from CPAP to weight loss.
Sleep Alcohol and sleep: why a nightcap keeps you from resting well
Why alcohol helps you fall asleep but disrupts the second half of the night, what studies show about REM sleep and recovery, and better ways to unwind.
Myth or factMyth or fact: melatonin is a safe, strong sleep aid
How much melatonin really helps you fall asleep, why supplement doses are unreliable and when melatonin actually makes sense.
SleepSleep and weight: how sleep loss affects appetite
How short sleep changes appetite hormones, what meta-analyses show about sleep and obesity and what a randomized trial found when people slept longer.
Sleep Teen sleep: why teens need more and fall asleep later
How much sleep teenagers need, why their body clocks shift later, what the American Academy of Pediatrics says about school start times and how parents can help.
SleepSleep and immunity: why short sleep raises your risk of colds
What a viral challenge study found about sleep duration and catching a cold, how sleep affects vaccine response and how to support immunity with sleep.
SleepEarly birds and night owls: chronotype and social jet lag
What a chronotype is, how social jet lag between workdays and weekends affects health and how natural light can shift your body clock earlier.
Sleep Night shifts: how to protect your health on shift work
How night and shift work are linked to accidents, diabetes, weight gain and heart disease, and practical tips for sleep, light and meals.
SleepSleep and memory: how the brain locks in learning overnight
How deep sleep and REM sleep help consolidate memories and skills, what naps add and why all-nighters before exams backfire.
Sleep Light and your body clock: how to reset your sleep schedule
Why light is the main signal for your circadian rhythm, what studies show about morning light, camping and evening screens, and how to use light to sleep better.
Sleep How sleep changes with age and what to do about it
How deep sleep and nighttime awakenings change across the lifespan, how much sleep older adults need and why sleeping pills are risky after 65.
SleepWaking up at night: what is normal and what is not
Why brief awakenings at night are a normal part of sleep, how they change with age and what to do when you cannot fall back asleep.
SleepSleep and your heart: how sleep duration is linked to heart attack and stroke
What a meta-analysis of 15 studies with 470,000 people found about short and long sleep, heart disease and stroke, and why sleep apnea matters.
SleepBetter sleep improves mental health: evidence from 65 trials
What a meta-analysis of 65 randomized trials found: improving sleep reduces depression, anxiety and stress, and the more sleep improves, the bigger the benefit.
SleepSleep and type 2 diabetes: how short sleep raises risk
What a meta-analysis found about short sleep, insomnia and diabetes risk, and why weekend catch-up sleep did not restore insulin sensitivity.
SleepBedroom temperature: how heat and cold affect sleep
How heat and humidity disrupt deep and REM sleep, why a cool room with warm bedding works best and simple ways to keep your bedroom comfortable.
Myth or factMyth or fact: you can catch up on sleep over the weekend
Can weekend recovery sleep undo a week of short nights? What a controlled experiment found about insulin sensitivity, snacking and weight.
SleepDrowsy driving: more dangerous than you think
How sleepiness raises the risk of serious crashes, what a case-control study found about short sleep and driving at night, and what to do when you feel drowsy.
Sleep Sleeping in the heat: how to rest on hot nights
Why hot nights shorten sleep, who is affected most and what helps: ventilation, a cool shower, light bedding and fans.
SleepSleeping in a cold home during a winter power outage
How to stay warm at night without heat and avoid danger: layers, sleeping bags, hot water bottles and why generators and stoves must never be used indoors.
Sleep Helping children sleep after frightening events and emergencies
How to help a child sleep after a disaster, emergency or scary news, what to do about nightmares, why a bedtime routine matters and when to get professional help.
Myth or factMyth or fact: mouth taping improves sleep
Does taping your mouth shut at night help snoring and sleep? What a systematic review found and who may be put at risk.
Myth or factMyth or fact: magnesium is the best remedy for insomnia
What is known about magnesium for sleep, why the viral "sleepy girl mocktail" does not treat insomnia and who should be careful with magnesium supplements.
Quizzes and calculatorsAll quizzes →
How much sleep do you need? Recommendations by age
Recommendations from the American Academy of Sleep Medicine and the National Sleep Foundation.
Editorial toolSocial jet lag calculator
The difference in your sleep midpoint between workdays and days off.
Editorial toolWhen should you stop drinking coffee? Calculator
According to a meta-analysis, have a regular coffee at least about 8.8 hours before bed.
Editorial toolWeekly sleep debt calculator
How much sleep you are missing compared with the recommended 7+ hours.
Editorial toolSleep hygiene: check your habits
8 habits with scientific support.
Editorial toolSnoring and sleep apnea: should you see a doctor?
Warning signs that are worth discussing with a doctor.
Editorial toolIs it chronic insomnia? Check the criteria
How often, how long and how much it affects your day.
Printables (PDF)All printables →
Two-week sleep diary
Record bedtime, wake time, awakenings, caffeine, alcohol and how you feel.
TrackerMonthly 24-hour sleep tracker
A visual sleep rhythm tracker that shows your schedule and social jet lag.
ChecklistBedtime routine checklist
A step-by-step wind-down routine with a weekly tracker.
CardSleep hygiene card
A bedroom card with the core rules for healthy sleep.
WorksheetBedtime worry journal
A worksheet for an evening "brain dump".
TrackerWeekly caffeine tracker
Record coffee, tea and energy drinks with times and how you slept.
PlanSleep plan for night shifts
A weekly schedule for shifts, sleep and light.
ChallengeChallenge: 30 days of a consistent wake time
The simplest change for better sleep: a regular wake time.