How to improve sleep quality: habits from the CDC and NIH that you can start tonight

What is sleep quality?

The Centers for Disease Control and Prevention (CDC) says quality sleep means uninterrupted, refreshing sleep, and that it is not just about how many hours you sleep but how well you sleep.¹ Signs of poor quality include trouble falling asleep, waking repeatedly during the night and feeling tired even after enough sleep.¹

The National Heart, Lung, and Blood Institute (NHLBI) uses the broader term sleep deficiency. It means not getting enough sleep, sleeping at the wrong time of day, not sleeping well or not getting all the types of sleep your body needs, or having a sleep disorder that prevents enough or good sleep.⁴ Quality and quantity are two parts of the same problem. For the hours, see how much sleep you need.

The habits grouped under the name sleep hygiene mostly work on one of three things: the clock (when you sleep), the room (where you sleep) and the evening (what you do before bed). The sections below follow that order.

Which habits do the CDC and NHLBI recommend?

The clock: when you sleep

Both the CDC and the NHLBI put a consistent schedule first.¹² The NHLBI explains why. Staying up late and sleeping in late on weekends can disrupt your body clock’s sleep-wake rhythm, so it advises keeping the weekend gap to about an hour.²

The NHLBI also notes that sleeping more on days off can be a sign you are not getting enough sleep. Extra sleep may help you feel better, but it can upset your body’s sleep-wake rhythm.⁵ The guide on sleep debt looks at why a weekend lie-in does not fully repay a short week.

Fix the wake time first. A fixed wake time is easier to keep than a fixed bedtime, and the bedtime follows from it.

The evening: the last 90 minutes

The NHLBI suggests using the hour before bed for quiet time and avoiding intense exercise and bright artificial light, such as from a TV or computer screen, because light may signal the brain that it is time to be awake.² The CDC’s own line is shorter: devices off at least 30 minutes before bed.¹

NIOSH, the CDC’s workplace safety institute, advises a relaxing routine starting about 1.5 hours before bed, with dim lighting and simple steps such as brushing your teeth and washing your face.³ The NHLBI mentions a hot bath or relaxation techniques before bed.²

Caffeine, alcohol and food

Caffeine is in coffee, tea, caffeinated soda and chocolate, and the NHLBI says a cup of coffee in the late afternoon can make it hard to fall asleep at night.² Nicotine is also a stimulant.² Alcohol is the trap. NIOSH says it may help you fall asleep but can cause sleep disturbances.³

Worked example: building a bedtime plan from a wake time

Suppose you must wake at 6:30 a.m. on workdays. The arithmetic below uses a 7 hour sleep window, the adult floor the CDC gives, and the cut-offs from the sources above.¹²³

Notice that the caffeine cut-off comes much earlier than most people expect. With an 11:00 p.m. bedtime, an 8 hour window puts the last coffee at 3:00 p.m.

The room: where you sleep

The CDC lists a quiet, relaxing and cool bedroom.¹ The NHLBI says quiet, cool and dark, with a dim night light fine if needed.² NIOSH gives numbers: about 65 to 68 °F for most people, a room dark enough to block lights, especially blue and white ones, and soft ear plugs if the space is noisy.³ It also says not to let pets or phones disturb your sleep.³

None of these needs equipment. A thermostat setting, a towel under the door and a charger outside the bedroom cover most of it.

Daytime: light, movement and naps

The NHLBI advises spending time outside every day when possible and being physically active.² The CDC lists regular exercise and a healthy diet.¹ Avoid intense exercise in the last hour before bed.²

Naps can help alertness, but they have a limit. The NHLBI says adults should nap for no more than 20 minutes, and take naps earlier in the afternoon if night sleep is hard.² It also says that napping cannot supply all the benefits of nighttime sleep, so you cannot really make up for lost sleep.⁵

Night shift workers and irregular schedules

When work conflicts with your body clock, the habits above still apply, but the NHLBI adds strategies for shift workers.²

• Take naps and raise the amount of time available for sleep.²
• Keep the lights bright at work.²
• Limit shift changes so your body clock can adjust.²
• Limit caffeine use to the first part of your shift.²
• Remove sound and light distractions in the bedroom during daytime sleep, for example with light-blocking curtains.²

If you still cannot fall asleep during the day or adapt to a shift schedule, the NHLBI says to talk with your doctor about other options.²

How to know whether it is working

Judge changes over two weeks, not two nights. The signs the CDC lists as poor quality are your checklist: trouble falling asleep, waking repeatedly, feeling tired after enough sleep.¹ If those fade, the habits are working.

A wearable can add trend data on sleep time, interruptions and heart signals. Read it as a log, not a verdict. The sleep score guide explains why scores differ between makers, and the stages guide covers what stage labels can and cannot tell you.

Frequently asked questions