What Is a Sleep Diary?

A sleep diary is a record of a person’s sleep habits and patterns. For example when they went to bed and when they woke up. There is no specific format that the diary needs to contain and more data can be included if preferred. Here are some recommendations of what you might want to include:

  • How many naps did you have and length of naps during the day
  • Amount of alcohol and the time of day
  • Amount of caffeine and the time of day
  • Time of last food and beverage intake before bed
  • Time of exercise during the day/evening
  • Number and duration of nighttime awakenings
  • Description of how you felt in the morning (for example, tired, groggy, awake, alert)


The following are additional things you might want to include:

  • The effects of room temperature on your sleep
  • How does your medication, prescribed or over the counter, affect your sleep
  • Effects and changes to sleep hygiene and how it affects your sleep
  • Compare sleep patterns when on vacation and when you’re not

There is no set rule as to how long you should keep the sleep diary. However, a minimum of a week is probably needed to see any type of pattern. Two weeks would be even better but more than a month is not necessary unless there are changes or other things you are testing.

How to Interpret a Sleep Diary?

A sleep diary is simple to interpret. A person can easily find patterns and make useful observations, even with no formal training or experience. Also, it is very beneficial to have a sleep professional (doctor, psychologist, nurse, sleep technician) look at the diary.

They have experience looking at the diaries of a lot of people, and therefore, have developed an understanding of which clinical sleep disorders correspond to which entries in the sleep diary.

How Reliable Is a Sleep Diary?

Since most people don’t remember what they did or ate during the day prior to sleep, or they forget to write in the diary until a day or two later, the reliability of sleep diaries have been questioned. In addition, we do not know what we do when we are asleep.

You can’t necessarily believe what people report about how much they slept last night. Tests with actigraphy have found that in general people overestimate how much they sleep.

Now, when you’ve learned what is a sleep diary and how to keep it, you might want to take a look at our newest mattress reviews, pick one that will perfectly work for your specific needs and sleep preferences and thus improve the overall quality of your sleep and rest.