CBT-I lesson 1: the sleep diary

The first step in CBT for insomnia is not a change. It is simply watching. For one to two weeks, you write down a few facts about each night in a sleep diary.

Every later lesson uses your diary. It shows what your nights are really like and lets you see progress you might not feel yet.

Why this step matters

CBT-I is the treatment that major medical groups recommend first for long-lasting insomnia, before sleep medicine.^1,2 Evidence for full CBT-I: Strong evidence

The whole program runs on your diary. In CBT-I, each step is planned from what your diary shows, week by week.¹ In lesson 2, you will use it to set your sleep window.

A diary also helps in other ways:

• It gives a fair picture. One bad night can color how we remember a whole week. Written notes are steadier than memory.
• It shows patterns. You may notice that coffee after lunch, a late nap, or a glass of wine lines up with worse nights.^4,5
• It helps your doctor. A clinical guideline for insomnia lists a sleep diary of about two weeks as a basic part of the first visit.³ The National Heart, Lung, and Blood Institute suggests keeping one before you see your doctor.⁵

What to write down

You can use a notebook, a printed form, or an app. The American Academy of Sleep Medicine offers a free printable diary that covers two weeks.⁴

Each morning, record these items for the night before:^3,4

Also jot down a few daytime notes:^3,4

• Naps or dozing, and how long
• Caffeine (coffee, tea, soda) and alcohol, with times
• Any sleep medicine or other medicines taken near bedtime
• Exercise, and how sleepy or tired you felt during the day

Write down what you actually do. Do not change your habits yet. This week is about getting a true starting point.

How to keep it

1. Pick your tool. A printed form, a notebook or an app. Keep it in the same place, such as by your coffee maker.
2. Fill it in each morning, soon after you get up. Memory fades fast, and the diary works best when you fill it in daily.⁴
3. Use best guesses. Do not watch the clock at night to measure things. Turn the clock away from the bed. A rough estimate in the morning is all you need.
4. Add daytime notes in the evening. Before bed, write down naps, caffeine, alcohol and medicines from that day.
5. Do not skip bad nights. Those nights matter most. If you miss a day, leave it blank rather than guessing days later.
6. Keep going for 7 to 14 nights. One to two weeks gives a fair average.^3,5 Keep the diary going through the rest of the program, too.^1,3

How to work out your sleep efficiency

Sleep efficiency tells you how much of your time in bed is spent asleep. The formula is: total sleep time divided by time in bed, times 100.³

1. Find your time in bed. Count from "into bed" to "out of bed." Example: 10:30 p.m. to 6:30 a.m. is 8 hours, or 480 minutes.
2. Add up your time awake in bed. Include time to fall asleep, minutes awake in the night, and time lying in bed after your final wake-up. Example: 45 + 60 + 30 = 135 minutes.
3. Find your total sleep time. Subtract time awake from time in bed. Example: 480 − 135 = 345 minutes, or 5 hours 45 minutes.
4. Divide and multiply by 100. Example: 345 ÷ 480 = 0.72. Times 100, that is 72%.

In this example, the person was asleep for about 7 of every 10 minutes in bed. That is below the 85% goal that many sleep experts use.³

Find your weekly average. At the end of the week, add up your total sleep time for all nights. Then add up your time in bed for all nights. Divide the first total by the second, and multiply by 100. Write down your average sleep time too. You will need both numbers in lesson 2.

Sleep diaries in later life

Sleep changes as we age. Many older adults take longer to fall asleep and wake more often, about 3 or 4 times a night on average. Deep sleep gets shorter, so it is easier to be woken.⁶ Getting up to use the bathroom is a common reason.⁶

These changes are normal, so a few short wakings will show up in almost any diary. Write them down anyway. Your clinician can help you decide what to aim for. See Sleep in later life for more.

If you care for someone with memory loss, you can keep a diary of what you see at night instead. Note bedtimes, wakings, naps and any restless times. This can help the doctor. See Sleep problems in dementia and the behavior diary.

Apps and devices

Some people prefer a phone app to paper. The VA offers Insomnia Coach, a CBT-I app made for everyone, not only veterans. It has an interactive sleep diary and a weekly plan.⁷ The VA's CBT-i Coach app is meant to be used along with a clinician who is treating you.⁸

Smartwatches and sleep trackers can be interesting, but CBT-I is built on the diary.¹ If you use a tracker, keep the diary as well. Doctors sometimes use a medical wrist sensor, called actigraphy, worn for 3 to 14 days to measure rest and activity.⁵

Common problems

I can't remember how long I was awake.

That is normal. Write your best guess, even "about an hour." Small errors even out across a week.

Writing about sleep makes me worry more.

Keep it short, about two minutes a day. Fill it in in the morning, not in bed at night. If worry about sleep is a big problem, lesson 4 has tools for that.

My nights were better than usual this week.

That happens. Sleep often varies from week to week. Keep the diary for a second week to get a fairer average.

I take sleep medicine. Should I stop while I keep the diary?

No. Keep taking it as prescribed and write it down. Talk with your doctor or pharmacist before changing anything. See Sleep medicines: what to know.

Next step

When you have one to two weeks of diary entries and your average numbers, go on to lesson 2: setting your sleep window.

When to get help

Talk with a doctor if your diary or your days show any of these:

• Loud snoring, gasping or pauses in breathing during sleep. These can be signs of sleep apnea, which needs its own treatment.
• An urge to move your legs in the evening. See restless legs syndrome.
• Dozing off during the day without meaning to, especially while driving.
• Low mood or worry that lasts most days. See Sleep, mood and anxiety.

If you have thoughts of suicide, call or text 988 any time. If someone is in danger right now, call 911.

Education only. This page is general information written from the sources listed. It is not medical, legal or financial advice and does not replace a doctor, therapist or lawyer who knows your situation. How we write and check pages.