Clear Sleep Guide: Expert Answers on How Much to Sleep

Healthy sleep fuels performance, mood, and overall well-being. In this interview, Dr. Mikhail Poluektov shares practical guidance on how much adults need to sleep, whether night owls exist, and what our dreams reveal about rest.

Dr. Mikhail Poluektov

Dr. Poluektov is a sleep medicine physician with a PhD. He serves as an associate professor of neurology and neurosurgery at Sechenov First Moscow State Medical University and leads the Sleep Medicine department at University Clinical Hospital No. 3.

1. How much sleep does an adult really need? What if you don’t get enough, or sleep too much?

Guidelines published in 2015 by international sleep experts recommend adults sleep between seven and nine hours per night for optimal recovery and health. Missing sleep has clear downsides, especially for the heart and blood vessels. Research shows that short sleep raises average blood pressure and increases the risk of high blood pressure by about 1.4 times.

Lower sleep duration is also linked to a higher likelihood of developing type 2 diabetes. In addition, cutting sleep by one or two hours can reduce immune function by roughly 1.5 times. The evidence on oversleep is less clear; it often appears related to underlying health issues rather than the extra sleep itself.

2. Do you have to go to bed by 11 p.m.?

The body’s internal clock signals melatonin, the sleep hormone, to start at night. But darkness alone does not guarantee an immediate bedtime. Light exposure and sensory input influence how our systems respond. In practice, most people naturally begin winding down around 9–10 p.m. and wake around 7 a.m., with melatonin production tapering as morning approaches.

Overall, aim for a sleep window roughly between 10 p.m. and 7 a.m. If your schedule shifts, you can adjust by a couple of hours, but consistent timing is key for melatonin and hormonal balance.

3. Are daytime naps necessary for adults?

A full night of adequate sleep makes daytime napping optional. If you miss sleep at night, short naps can help restore alertness and cognitive function. A brief nap of 10–30 minutes is best; longer naps can leave you groggy and disrupt nighttime sleep.

4. Why do some people fall asleep quickly while others struggle, even when tired?

A healthy sleeper typically falls asleep within 15 minutes. If it takes longer and this happens more than twice a week, the person may have insomnia and should seek medical advice. Sleep hygiene basics include:

1. Establish a fixed bedtime and wake-up time to regulate the body’s internal clock.
2. Create a calm pre-sleep routine by reducing stimulating activities and screens for about an hour before bed.
3. Minimize night-time disturbances in the sleeping area (light, noise, and comfortable temperature).

Starting with these habits helps many people improve sleep quality.

5. Why are some people night owls and others early birds?

True night owls and early birds are relatively rare—about 10% each. Most people fall into a middle category and can adapt to different schedules. Genetic factors account for roughly half of this pattern, while social and environmental factors explain the other half.

If your work requires early rising and you’re naturally a night person, gradually shift your schedule or try to align your main activities with your preferred times when possible.

6. Why do I still feel tired after enough sleep?

Most often, daytime fatigue comes from the nervous system being overstressed by modern life—emotions, information overload, and constant alertness. If you still feel tired after adequate hours, consider reducing mental load and stress before bed.

7. Do dreams have meaning or prophetic value?

Scientific opinion on dream meaning varies. Some researchers view dreams as a byproduct of memory processing, while psychologists explore symbolic interpretations. Dreams may reflect daily experiences and emotions, but they are not reliable prophecies. Still, they can offer insights into thoughts and feelings.

8. Can you influence your dreams?

Lucid dreaming—a state where you know you are dreaming and can influence the dream—exists and can be learned, but it takes time and effort. The practical benefits are limited, and most people do not need to pursue it. For sleep health, standard treatment and sleep hygiene are typically more effective.

9. What happens to the brain while we sleep?

During sleep, the brain continues to organize and consolidate memories. It processes daily experiences and may creatively integrate them into new ideas. Sleep also accelerates the brain’s cleanup processes, helping remove waste products such as certain proteins linked to cognitive decline by a substantial amount.

10. Are screens before bed harmful? What about short daylight days?

Yes, evening screen use can lower melatonin by about 23% after roughly two hours, which may delay sleep onset. Melatonin supports sleep but does not directly control sleep quality; comfort and calmness before bed are often more important. In autumn and winter, shorter daylight can slightly increase total sleep time while lowering perceived sleep quality, but the changes are usually not drastic for most people.

Expert comment

Dr. Poluektov emphasizes the importance of a consistent sleep schedule and a relaxed pre-sleep environment for better rest. He notes that high mental load and stress are common barriers to restful sleep, even with enough hours.

Summary

Most adults need seven to nine hours of sleep per night. Maintaining regular bed and wake times, a quiet and dark bedroom, and a brief, early-evening wind-down supports health. Short daytime naps can help if you’re sleep-deprived, but long naps may hinder night sleep. If sleep problems persist, seek medical guidance for a personalized plan.

Key insight: Consistent, quality sleep forms the foundation of good health, and small routine changes often yield the biggest improvements.