Sleep is when your body repairs tissue, consolidates memories, clears waste from the brain and balances hormones that control appetite and blood sugar. Yet about one in three adults regularly gets less sleep than recommended. So how much sleep do you need? The answer depends mainly on your age, and there is a healthy range rather than a single magic number.
Recommended sleep by age
| Age group | Recommended sleep per 24 hours |
|---|---|
| Newborns (0–3 months) | 14–17 hours |
| Infants (4–12 months) | 12–16 hours, including naps |
| Toddlers (1–2 years) | 11–14 hours, including naps |
| Preschoolers (3–5 years) | 10–13 hours, including naps |
| School-age children (6–12 years) | 9–12 hours |
| Teenagers (13–18 years) | 8–10 hours |
| Adults (18–64 years) | 7–9 hours |
| Older adults (65+ years) | 7–8 hours |
Why teenagers struggle with sleep
During adolescence, the body clock naturally shifts later, so teens often do not feel sleepy until 11 pm or later. Combined with early school start times and screens, many teens get far less than the 8–10 hours they need, which affects mood, learning and safety on the road.
Do older adults need less sleep?
Not much less. What changes is sleep structure: older adults spend less time in deep sleep, wake more often during the night and tend to feel sleepy earlier in the evening. Frequent nighttime waking, pain, needing the bathroom and medications can all reduce sleep quality.
Signs you are not getting enough sleep
- Needing an alarm to wake up and hitting snooze repeatedly
- Feeling drowsy during the day, especially in meetings, while reading or driving
- Falling asleep within minutes of lying down
- Irritability, low mood or anxiety
- Difficulty concentrating or remembering things
- Increased cravings for sugary or high-calorie foods
- Getting sick more often
- Sleeping much longer on weekends
What happens when you don’t sleep enough
- Weight gain: short sleep raises the hunger hormone ghrelin and lowers the fullness hormone leptin.
- Blood sugar problems: even a few nights of restricted sleep reduce insulin sensitivity.
- Heart health: regularly sleeping less than 7 hours is linked to high blood pressure, heart disease and stroke.
- Weaker immunity: in one study, people sleeping less than 6 hours were about four times more likely to catch a cold after exposure to the virus. Learn more in our guide to supporting your immune system.
- Mental health: poor sleep and anxiety or depression feed into each other.
- Accidents: drowsy driving causes thousands of crashes every year.
Can you sleep too much?
Regularly sleeping more than 9–10 hours as an adult is associated with health problems, but often as a sign of an underlying issue, such as depression, sleep apnea, thyroid problems or other illnesses, rather than the cause. If you sleep a lot and still feel unrefreshed, talk to a doctor.
How to get more quality sleep
- Keep a consistent schedule, waking at the same time every day, including weekends.
- Get daylight in the morning to set your body clock.
- Limit caffeine after midday and avoid alcohol close to bedtime.
- Keep your bedroom cool, dark and quiet, around 16–19°C (60–67°F).
- Create a wind-down routine: dim lights, put screens away and read or stretch for 30–60 minutes.
- Exercise regularly, ideally not intensely right before bed. Our strength training guide is a good place to start.
- Avoid heavy meals late at night.
- If you can’t sleep after about 20 minutes, get up and do something calm in dim light until you feel sleepy.
When to see a doctor
Talk to a doctor if you have trouble sleeping three or more nights a week for three months, feel very sleepy despite enough time in bed, or if a partner notices loud snoring, gasping or pauses in breathing. Sleep apnea and insomnia are common and very treatable; cognitive behavioral therapy for insomnia (CBT-I) is the recommended first treatment for chronic insomnia.
Frequently asked questions
Is 6 hours of sleep enough?
For most adults, no. A very small number of people have genetic variants that let them function on less sleep, but most people who believe they are fine on 6 hours show measurable drops in alertness and performance.
Can you catch up on sleep at the weekend?
Extra weekend sleep can partly relieve short-term sleepiness, but it does not fully reverse the effects of regular weekday sleep loss and can disrupt your body clock.
Do naps count toward total sleep?
For young children, yes. For adults, short naps of 20–30 minutes can boost alertness, but they are not a full replacement for nighttime sleep.
Medical disclaimer: This article is for general education only and is not a substitute for personal medical advice. See a doctor about persistent sleep problems, excessive daytime sleepiness or loud snoring.
