Key takeaways
- Getting enough sleep is essential for overall health, helping to prevent disease, boost immunity, and improve mental well-being.
- The amount of sleep needed varies by age, with adults typically needing 7 to 9 hours. However, the amount of sleep a person needs can also depend on their lifestyle, health conditions, and genetics. Anyone with questions about sleep health should talk with a doctor.
- Improving sleep quality involves maintaining a consistent sleep schedule, exercising daily, avoiding caffeine and nicotine, minimizing light and noise, and creating a relaxing bedtime routine.
Experts believe that sleep is just as important to a person’s health as food and water. Getting the right amount of sleep can help prevent disease, boost immunity, and improve mental health. Still, many people are not getting enough sleep.
Building a healthy sleep pattern may require tweaking the schedule or lifestyle. While this can be challenging at first, the benefits of proper sleep are worth the effort.
Though there are general guidelines, some people need more sleep than others, due to their lifestyle, any health conditions, and their genetic makeup.
The
| Age | Recommended hours of sleep |
|---|---|
| 0 to 4 months | this varies, but may range from 8 to 18 hours |
| 4 months to 1 year | 12 to 16 hours |
| 1 to 2 years | 11 to 14 hours |
| 3 to 5 years | 10 to 13 hours |
| 6 to 12 years | 9 to 12 hours |
| 13 to 18 years | 8 to 10 hours |
| 18 years and older | 7 to 9 hours |
The following chart can help a person figure out when they need to be going to bed to get 8 hours of sleep a night.
The time it takes to fall asleep can vary slightly between people. One 2023 meta-analysis reported that adults with no significant health conditions — including no sleep problems — took an average of 11.7 minutes to fall asleep.
The calculations below assume that a person needs 15 minutes, but if someone tends to take longer, they should adjust their bedtime accordingly.
| Wake-up time | Bedtime (to get 8 hours of sleep): |
|---|---|
| 4:00 a.m. | 7:45 p.m. |
| 4:30 a.m. | 8:15 p.m. |
| 5:00 a.m. | 8:45 p.m. |
| 5:30 a.m. | 9:15 p.m. |
| 6:00 a.m. | 9:45 p.m. |
| 6:30 a.m. | 10:15 p.m. |
| 7:00 a.m. | 10:45 p.m. |
| 7:30 a.m. | 11:15 p.m. |
| 8:00 a.m. | 11:45 p.m. |
| 8:30 a.m. | 12:15 a.m. |
To be properly rested, the body must go through several stages of sleep repeatedly in multiple cycles per night, including rapid eye movement (REM) sleep and non-REM sleep.
The stages of sleep include:
- Stage 1 non-REM: This lasts for only a few minutes. Breathing, heart rate, and brain waves begin to slow.
- Stage 2 non-REM: This stage occurs before the body enters deep sleep. The muscles relax even more, and body temperature drops.
- Stage 3 non-REM: A person needs to reach this stage of deep sleep to feel rested, and it lasts longer in the first half of the night. Breathing and heart rate slow to their lowest levels.
- REM sleep: Within 90 minutes of falling asleep, a person enters REM sleep. The brain becomes more active, the most dreaming occurs, and the arms and legs become temporarily paralyzed.
If the body does not go through this cycle several times a night, the person may wake feeling fatigued and unfocused.
Resources for healthy sleep
To discover more evidence-based information and resources on the science of healthy sleep, visit our dedicated hub.
Getting enough sleep may help prevent or reduce the risk of certain health conditions.
The
Is there such a thing as too much sleep?
The
- young adults
- individuals who are ill
- individuals recovering from sleep deprivation
However, some research has linked health risks to regularly oversleeping.
A 2025 systematic review reported that prolonged sleep duration was consistently linked to higher risks of high blood pressure, stroke, coronary artery disease, and heart attack. A 2023 study also reported that both short sleep duration (5 hours) and long sleep duration (12 hours) led to a higher risk of type 2 diabetes compared to sleeping for 8 hours. Still, many other studies have investigated oversleeping and not found it to cause negative health effects.
More research is needed to confirm any cause-and-effect relationship between oversleeping and health problems, as well as to understand the level of risk associated with excessive sleep.
Sometimes, sleeping too much can be a symptom of a health condition, such as depression, thyroid disorders, and sleep disorders.
Anyone who is concerned about their sleep habits, regularly sleeps more than 9 hours, or experiences other symptoms alongside excessive sleep should contact a doctor for advice.
Recent research suggests that a lack of sleep could make a person more likely to gain weight.
A 2024 meta-analysis concluded that short sleep duration led to a higher risk of central obesity, whereas long sleep duration did not.
A possible reason for the association is that being tired may lead to behaviors such as reduced physical activity, snacking, and a higher intake of foods rich in fats and carbohydrates.
Overall, it is likely a good idea for anyone looking to maintain a moderate weight to aim for 7 to 9 hours of sleep.
Getting quality sleep sometimes requires only simple tweaks in a routine. Other times, a person may need to prioritize approaches to improve sleep.
Here are some ways to
- Be consistent: Going to bed and waking up at the same time every day helps the body develop a rhythm, which may make it easier to fall asleep and wake up feeling rested.
- Be physically active each day: Physical activity may improve sleep quality and help people who have chronic insomnia.
- Avoid caffeine and nicotine: Avoid these stimulants — especially within a few hours of bedtime — as both can take several hours or longer to leave the bloodstream, potentially interfering with sleep.
- Drown out sound and light: Using earplugs, a white noise machine, and room-darkening curtains or window treatments can help.
- Turn off TVs, smartphones, and tablets at least 2 hours before bed: The blue light that these devices can emit can suppress melatonin, a hormone necessary for asleep.
- Try relaxing alternatives: Instead of looking at screens, try taking a warm bath, reading a book, or meditating.
In many cases, lifestyle adjustments can improve sleep quality and quantity.
However, if these changes are not effective, talk with a doctor. Health conditions, certain medications, and other factors can affect sleep quality, and a doctor can help identify and treat any underlying causes.
If a person frequently has trouble sleeping, they may want to ask their doctor about a sleep study. This can help identify sleep disorders.
Sleep is vital to health — being well-rested can help prevent certain health conditions.
To get the recommended 7 to 9 hours each night, it is important to get to bed at the right time, which may involve creating a routine. For many people, this can make a big difference.
If a person has tried various recommendations and strategies and tiredness or sleeping problems persist, they should visit a doctor.