The quality of our sleep is essential to long-term health. Sleep restores physical and mental fitness. What defines restorative sleep varies with age. Here are some handy numbers you can use to evaluate your own sleep health.
Sleep Quantity
How much sleep do we need? The National Institutes of Health notes that adults who sleep less than seven hours each day have more health issues than people who sleep more then seven hours. Our needs for sleep change as we grow and age. Sleep helps the body heal, activates the immune system, and allows the mind to organize thoughts and memories. Young people require more sleep given the release of growth hormones throughout the night.*
- 0–3 months 14–17 hours
- 4–12 months 12–16 hours (including naps)
- 1–2 years 11–14 hours (including naps)
- 3–5 years 10–13 hours (including naps)
- 6–12 years 9–12 hours
- 13–17 years 8–10 hours
- 18–60 years 7 or more hours
- 61–64 years 7–9 hours
- 65 years + 7–8 hours
Percentage of American adults who get less than the recommended minimum seven hours of sleep.
- Age 18-44 38.3%
- Age 45-64 38.6%
- Age 65 and older 28.1%
Sleep quality
Sleep is more than just hours spent in bed. Researchers have identified three stages of sleep, from light to deep, with a fourth stage in which rapid eye movement (REM) indicates dreaming.* Deep sleep is also known as Delta Sleep after the distinctive delta wave pattern of brain activity. This stage is viewed as essential for restorative sleep. Experiencing all four stages constitutes one sleep cycle. The duration of each stage varies through the night, with shorter light stages and longer deep and REM stages.
- Stage One Lightest Sleep 1-7 minutes
- Stage 2 Light Sleep 10-25 minutes
- Stage 3 Deep Sleep 20-40- minutes
- Stage 4 REM Sleep 10-60 minutes
- Average duration of a cycle 90 minutes
- Number of cycles per night 4-6
- Percentage of non-REM sleep 75%
