Want to sleep better? Which habits can you change?

Many things are in your own hands. The CDC and the US National Heart, Lung, and Blood Institute (NHLBI) advise going to bed and waking at the same time every day, turning off electronic devices at least 30 minutes before bed, avoiding caffeine from the afternoon, avoiding large meals and alcohol before bed, napping for no more than 20 minutes, and keeping the bedroom quiet, dark and cool. Adults do not need exactly 8 hours, but should regularly get at least 7.

Want to sleep better? Which habits can you change?

The sleep habits that public health agencies recommend are all things you can adjust yourself, and it makes sense to work on several at once, because sleep is shaped by several factors across the same day.

Habits the CDC recommends

• Go to bed and get up at the same time every day.
• Keep your bedroom quiet, relaxing and at a cool temperature.
• Turn off electronic devices at least 30 minutes before bedtime.
• Avoid large meals and alcohol before bedtime.
• Avoid caffeine in the afternoon or evening.
• Exercise regularly and eat a healthy diet.

What the NHLBI adds

• Keep the same sleep schedule on weeknights and weekends, with no more than about an hour's difference.
• Use the hour before bed for quiet time, and avoid intense exercise and bright artificial light.
• Spend time outside every day when possible, and be physically active.
• Take a hot bath or use relaxation techniques before bed.
• Avoid nicotine, such as cigarettes.

Do I really need 8 hours of sleep every night?

Not exactly 8. In their 2015 joint consensus statement, the American Academy of Sleep Medicine (AASM) and the Sleep Research Society recommended that adults aged 18 to 60 sleep at least 7 hours a night on a regular basis. Eight hours is one figure within the recommended range, not a rule everyone has to hit. People need different amounts within the same range: some do well on 7 hours, others need closer to 9.

How many hours each age group needs

The National Sleep Foundation publishes recommended ranges by age.

What time should I go to bed?

There is no fixed time for everyone. Count back from the time you need to wake. For example, if you wake at 6 a.m. and want at least 7 hours, aim to be asleep by 11 p.m.

I drink coffee in the afternoon and find it hard to sleep at night. Is that related?

It can be. The NHLBI notes that the effects of caffeine can last up to 8 hours, so a cup of coffee in the late afternoon can make it hard to fall asleep.

Research on caffeine timing

Drake and colleagues (2013) gave 12 adults 400 mg of caffeine at bedtime, 3 hours before bed and 6 hours before bed, compared with a placebo, and measured their sleep at home. Every timing disturbed sleep significantly. Even at 6 hours before bed, caffeine reduced total sleep by more than 1 hour, and the authors concluded that substantial caffeine should be avoided for at least 6 hours before bedtime.

Caffeine is not only in coffee

The NHLBI lists caffeinated soft drinks, coffee, tea and chocolate as sources. Even if you stop coffee after lunch, iced tea or a soft drink in the evening still contains caffeine. If you go to bed at 10 p.m., stopping caffeinated drinks at around 2 p.m. leaves 8 hours before bedtime.

Does using my phone before bed make it harder to sleep?

It can. The NHLBI advises avoiding bright artificial light in the hour before bed, and the CDC advises turning off electronic devices at least 30 minutes before bedtime. Beyond the light, news, work messages and short videos keep the brain alert, and scrolling usually takes longer than planned, pushing bedtime later without you noticing.

• Set a time to put the phone down, and use that time to read, listen to quiet music or take a warm bath.
• Turn on do-not-disturb mode for the night.
• Charge the phone outside the bedroom if you can.

How should I set up my bedroom, naps and exercise?

A quiet, dark and cool bedroom

The NHLBI advises keeping the bedroom quiet, cool and dark; a dim night light is fine if needed. Blackout curtains block outside light, and earplugs or steady background sound reduce noise.

Naps of 20 minutes or less

The NHLBI advises adults to nap for no more than 20 minutes. Long naps, or naps close to the evening, can leave you less sleepy at bedtime.

Timing exercise

Moving and spending time outdoors during the day is part of good sleep habits, but the NHLBI advises avoiding intense exercise in the hour before bed.

Evening meals and drinks

The NHLBI advises avoiding heavy or large meals within a few hours of bedtime (a light snack is fine) and avoiding alcoholic drinks before bed.

How do I know if I'm getting enough sleep, and when should I see a doctor?

The practical test is not the number on a sleep tracker but how you get through the next day.

• You get out of bed without dragging.
• You stay alert through the afternoon.
• You feel sleepy at your usual bedtime.

The CDC advises talking to a healthcare provider if you regularly have problems sleeping or notice signs of common sleep disorders. If you take regular medication, ask your doctor or pharmacist whether it affects sleep.