What It Means
Sleep debt is the gap between the sleep your body needs and the sleep you actually get, added up night by night. CDC and the American Academy of Sleep Medicine (AASM) recommend 7 or more hours a night for adults. By that measure, an adult who sleeps 6 hours on each of five work nights runs up about 5 hours of sleep debt that week.
Try It: Add Up This Week's Sleep Debt
Enter a typical week. The tool adds up the hours you fall short and keeps any extra sleep on nights off separate. CDC and AASM recommend 7 or more hours for adults.
No shortfall at these numbers.
Short by less than an hour a night on average this week.
Short by an hour or more a night on average. AASM lists daytime sleepiness and trouble concentrating as common signs.
The extra hours are shown apart because they don't cancel the shortfall. In an NIH-funded study, two days of sleeping in didn't undo what short nights did to metabolism.
How People Say It
- "I'm running on a serious sleep debt this week."
- "Five hours a night since Monday, I'm wrecked."
- "I'll sleep in Saturday and make it up."
The Breakdown
Formula
Hours short on a night = the sleep you need minus the sleep you got. A night with enough sleep counts as zero. Sleep debt for the week = the hours short on each night, added together. For adults, CDC and AASM put the need at 7 or more hours.
Worked example. An adult who needs 7 hours a night:
| Nights | Sleep each night | Short each night | Short in total |
|---|---|---|---|
| 5 work nights | 6 hours | 1 hour | 5 hours |
| 2 nights off | 8 hours | 0 | 0 |
| Whole week | 6.6 hours on average | 5 hours |
What the result means. This person averages about 6.6 hours a night, under the adult minimum, and ends the week 5 hours short. The two long nights on the weekend show up in the tool as extra sleep, kept apart from the total, because they don't pay the debt back. In an NIH-funded study, adults who slept at most 5 hours a night on weekdays and then slept in for two days still showed the harm short sleep did to their metabolism.
A total of 7 hours or more means you're short by an hour or more a night on average. AASM's advice is a bedtime early enough to cover your full hours every night.
Good to Know
AASM names daytime sleepiness as the most common sign of not getting enough sleep. Other signs it lists include trouble concentrating and paying attention, lower energy, reduced alertness, distractibility, irritability and fatigue. When short sleep comes from late bedtimes, AASM's answer is to sleep longer each night. If you get full nights and still feel sleepy during the day, talk to a doctor.
FAQ
Can you catch up on sleep debt over the weekend?
Not fully. In an NIH-funded study of 36 healthy adults, people who slept at most 5 hours a night during the week and then slept in for two days still showed the harm to metabolism, and the weekend sleep seemed to make it worse. AASM advises keeping one wake-up time all week instead.
What are the symptoms of sleep debt?
AASM names daytime sleepiness as the most common one. Others include trouble concentrating, lower energy, reduced alertness, distractibility, irritability and fatigue.
How many hours of sleep do I need to avoid sleep debt?
For adults, CDC and AASM recommend 7 or more hours a night. CDC's table lists 7 to 9 hours for ages 61 to 64, 7 to 8 hours for 65 and older, and more for children and teens.
Do It in Buhata
Reminders
Set a Reminder in Buhata for a bedtime that leaves room for the hours you need before your alarm goes off.
Open BuhataRelated Terms and Categories
- Sleep schedule
The set times a person goes to bed and gets up each day, planned so they get the hours of sleep recommended for their age.
- Power nap
A short daytime nap, about 20 minutes or less, meant to lift alertness without the grogginess that can follow a longer sleep.
- Afternoon slump
The dip in energy and focus many people feel in the early to mid afternoon, linked to the body's daily hormone rhythm and to what and how much was eaten at lunch.
- Sleep hygiene
The everyday habits and bedroom setup that make it easier to fall asleep and stay asleep, like a steady wake-up time and a quiet, cool room.
- Circadian rhythm
The body's roughly 24-hour cycle of physical, mental and behavioral changes, such as sleepiness at night, kept in time by a clock in the brain that follows light.
Sources
NIH, "Weekend catch-up can't counter chronic sleep deprivation" (NIH Research Matters); American Academy of Sleep Medicine, Sleep Education, "Insufficient Sleep Syndrome"; CDC, "About Sleep"
- www.nih.gov/news-events/nih-research-matters/weekend-catch-cant-counter-chronic-sleep-deprivation
- sleepeducation.org/sleep-disorders/insufficient-sleep-syndrome
- www.cdc.gov/sleep/about/index.html
Last updated .