A 30-item sleep hygiene checklist — do them all and insomnia is almost impossible

From yesterday's caffeine to this morning's sunlight, from bedroom temperature to weekend wake time — 30 small variables that affect sleep, in a checkable list.

Dr. Kim Sumyeon

Sleep medicine specialist

8 min read

TL;DR

Break sleep into 30 checkable items — timing (caffeine cutoff, dinner), environment (temperature, light, noise), behavior (screens, exercise, bath), mental (worry notes, meditation), rhythm (consistent wake time, morning light). Check 5 or more new items each week and you'll notice clear change within three weeks.

"Sleep hygiene" is the most powerful non-drug tool in sleep medicine. But it can sound abstract — what exactly should I do? This article lists every variable that affects sleep as 30 concrete checkboxes. Print it and stick it next to your bed.

A neatly arranged peaceful bedroom — Sleep is built not by one big thing but by thirty small ones.

A. Timing (5 items)

No caffeine after 2 PM (or noon if you're sensitive)
Finished dinner at least 3 hours before bed
No alcohol within 3 hours of bed
All screens (phone, TV, laptop) off at least 1 hour before bed
Last full glass of water 1 hour before bed (only sips after)

B. Bedroom environment (6 items)

Bedroom temperature is 18–20°C
Dark enough that you cannot see your fingers (or use a mask)
White noise or below 30 dB
Mattress under 7 years old and matched to your body
Pillow keeps head, neck, and spine in a straight line on your side
Air ventilated 5 minutes 30 minutes before bed

C. Behavior (5 items)

30+ minutes of outdoor activity or exercise today
Heavy evening exercise ended at least 3 hours before bed
Warm shower or bath 1–2 hours before bed
Bed used only for sleep (no work, TV, eating)
If sleep doesn't come within 20 minutes, get up and move to another room (stimulus control)

Evening journaling and tea — The 5-minute ritual before bed builds tonight's sleep.

D. Mind / psychology (5 items)

"Worry note" 1 hour before bed — write every concern on paper
Don't watch the clock in bed (move it out of sight)
One or two rounds of 4-7-8 breathing
If sleep doesn't come, don't calculate "how little I'll get"
Recall (or write) 3 things you were grateful for today

E. Circadian rhythm (5 items)

Woke at the same time (±30 minutes) — including weekends
Natural light exposure within 30 minutes of waking (5–10 min)
Breakfast included protein (cortisol normalization)
5-minute walk or outdoor break after lunch
Warm-color dim lighting in the evening (amber)

F. Adjuncts (4 items)

Magnesium 200–400 mg an hour before bed if needed
Minimized exposure to alcohol, nicotine, and other stimulants today
Sleep tracker / app for long-term pattern recognition
Weekly review of your patterns — what was different on good nights vs bad?

How to use these 30 items

You can't hit all 30 at once. Build up in stages:

Week 1: Group A (5 timing items) + #6 (bedroom temperature)
Week 2: Add Group B (5 environment items)
Week 3: Add Groups C and D
Week 4: Add Groups E and F

If you can hold 25+ items consistently after a month, 90% of typical sleep problems disappear. If sleep still doesn't come, a medical cause like apnea may be involved — see a clinic.

The 5 with the biggest effect (priority for the time-poor)

Cut caffeine after 2 PM (#1)
Same wake time daily (#22)
Morning sunlight 5–10 min (#23)
Bedroom 18–20°C (#6)
Screens off 1 hour before bed (#4)

Just these five produce a measurable improvement for over 80% of adults.

A cup of tea in the evening — Start with the easiest of the 30 — try it for one week.

One more — don't feel guilty about the items you missed

Perfectionism is the enemy of sleep. Hitting 20 of 30 is plenty. Don't think "I had caffeine today, I ruined it"; think "tomorrow I'll move it earlier to 11 AM." The harder you press sleep, the further it pulls away.

Frequently asked questions

Which of the 30 items is most commonly skipped?

Consistent weekend wake time (#22) and "bed for sleep only" (#15). Both aren't hard to follow — they're hard to remember without conscious effort. Phones in bed, weekend sleep-ins — fixing just these two produces a big change.

If I had to pick just one, which is most effective?

"Same wake time every day" (#22). This single thing anchors the entire circadian rhythm; other variables follow on their own. Wake time matters more than bedtime — when wake time is consistent, bedtime naturally falls into place.

I follow 80% of the list and still can't sleep

Suspect a medical cause. The most common are (1) sleep apnea, (2) chronic pain, (3) thyroid issues, (4) depression/anxiety. Keep a sleep diary for a week and consult a psychiatrist or sleep clinic. There are domains that sleep hygiene alone cannot fix.

A worry note doesn't empty my head

One tip: write "tomorrow's actions," not "worries." When you write the action you'll take about each concern in one line, your brain marks it as "handled." Also write slowly, not quickly — the act of writing itself activates the parasympathetic.

I have no time to go outside for morning light. What should I do?

Five minutes is enough — brush your teeth on the balcony, get off the bus one stop early and walk, or place a 10,000-lux light therapy lamp on your desk for 15 minutes. The most realistic option for Korean office workers: a 5-minute walk on the way to work — that 5 minutes builds tonight's sleep.