On average, how many hours do you sleep each night? For most healthy adults, guidelines recommend at least seven hours of sleep.
But these are general recommendations, not strict rules. “Some people need less than seven hours, while others may need more,” says Eric Zhou of the Division of Sleep Medicine at Harvard Medical School.
We get it: You know people who swear they only need five hours of sleep a night, but feel foggy unless you get in eight to nine hours. The main reason for individual differences is that we often look at sleep in the wrong way.
“Instead of focusing exclusively on the number of hours we sleep per night, we should also consider our sleep qualityJoe says.
Sleep quality refers to how well you sleep at night. Did you sleep straight through? Or have you had periods where you woke up? If so, did it take you long to fall asleep? How did you feel when you woke up?
“If you wake up refreshed and feel like you have the energy to get through your day, then I would worry less about the exact number of hours you sleep,” says Zhou.
Sleep quality is vital to our overall health. Research shows that people with poor sleep quality are at higher risk of diabetes, heart disease, stroke and mental health problems such as anxiety and depression.
And that’s not all. “Poor sleep can also increase daytime fatigue and make it harder to enjoy life,” says Zhou.
Still, it’s normal for people’s sleep patterns to change over time. “A lot of people won’t sleep in their 50s and 60s exactly like they did in their 20s,” Zhou says.
Many of these changes are age-related. For example, your circadian rhythm—which regulates many bodily functions, including our sleep-wake cycle—can naturally become disrupted over time. This means that people spend less time each night in slow-wave restorative sleep.
The production of melatonin, the sleep hormone, also gradually declines with age. “As a result of these changes, as we get older, we may start to wake up earlier than when we were younger, or wake up more often during the night,” says Zhou.
How can you better understand the factors that likely contribute to the quality of your sleep? One way is to keep a sleep journal where you track and record your sleep.
Each day, record the time you went to bed, how long it took you to fall asleep, whether you had any awakenings during the night (and if so, how long you were awake), and what time you woke up. Also, keep track of how you feel after waking up and at the end of the day.
“After a week or two, review the information to see if you can identify certain patterns that may be affecting your sleep quality, then make adjustments,” says Zhou.
For example, if you have trouble falling asleep, go to bed half an hour later than usual, but keep the same wake-up time. “It’s common for people who struggle with sleep to try to get more sleep by staying in bed longer, but this disrupts their sleep patterns and reduces their quality,” says Zhou.
Three key strategies to maintain the quality of your sleep
Other strategies that can help maintain good sleep quality include:
- maintaining a consistent wake-up time, especially on weekends
- limiting daytime naps to 20 to 30 minutes and at least six hours before desired bedtime
- being physically active.
When it comes to sleep quality, consistency is vital. “People with good sleep quality often have a predictable sleep window where their sleep occurs,” Zhou says. “Good sleepers are likely to sleep about the same number of hours and sleep through the night.”
It’s unrealistic to expect perfect sleep every night. “If you’re having trouble sleeping one or two nights a week, it may be related to the natural ebb and flow of life,” says Zhou. “You may have eaten too much that day, had too much alcohol while watching football, or had a stressful argument with someone. When tracking sleep quality, look at your overall sleep health week by week, not how you slept this Tuesday compared to last Tuesday.
If you’re doing all the right things about your sleep but still don’t feel rested after waking up, talk to your doctor. This can help rule out a sleep disorder such as sleep apnea or another health problem that can interfere with sleep, such as acid reflux or high blood pressure. Other factors that can affect the quality of your sleep include taking multiple medications, depression, anxiety, loneliness, and environmental changes such as temperature, noise, and light exposure.