When a clinician asks how often you have headaches, “quite a lot lately” may be the most honest answer you can give. Painful days blur together, and it can be difficult to remember how long an episode lasted or what you took for it.
A headache diary can turn those impressions into a record you can discuss. It does not need elaborate charts or a paid app. Its value comes from a few consistent details and a clear distinction between what happened and what you think might have caused it.
Do not let record-keeping delay care
Before setting up a diary, consider whether the headache needs attention now. The NHS headache guidance, reviewed in 2024, advises emergency care for a sudden, extremely painful headache or headache with symptoms such as weakness, seizure, confusion, trouble speaking or walking, or loss of vision. Headache after a recent head injury or with a high fever and stiff neck also needs emergency assessment.
Use your local emergency service, such as 999 in the UK or 911 in the US. Do not drive yourself if emergency care is needed.
The NHS also advises urgent medical advice for headache with eye or vision problems, vomiting, jaw pain while eating or a tender scalp, or headache triggered or worsened by coughing, bending or exercise. This is not an exhaustive list. Seek help for a worrying change.
Arrange a clinical appointment for recurring headaches or headaches that worsen or do not improve with self-care. Bring whatever notes you have rather than waiting to complete a diary.
Choose the simplest format you will use
A notebook, a printable calendar or a private note on your phone can all hold the same information. Choose based on what is easiest when you are uncomfortable, not which option offers the most graphs.
If you use an app, look at what you can export before investing time in it. A record is less helpful at an appointment if the relevant entries are trapped behind several screens or cannot be shared in a readable form.
Think about privacy too. Headache notes may include medication, menstrual information and details about daily life. Decide where you are comfortable storing that information and who can access it.
If writing during an episode is difficult, make a brief note afterward. An approximate time labeled as approximate is more useful than a precise-looking guess.
Record the core details consistently
NICE guideline CG150, with diary recommendations dating from 2012 and checked in September 2026, suggests recording headache frequency, duration and severity; accompanying symptoms; prescribed and over-the-counter headache medicines; possible triggers; and the relationship to menstruation where relevant.
The guidance describes a minimum of eight weeks when a diary is used to help assessment. That is a recording period, not a requirement to wait eight weeks before seeking help. Your clinician may ask for a particular format or timeframe.
For each episode, note when it began, when it ended if known, and how it affected you. Use the same approach to severity each time. You might use a number scale alongside plain words, but do not worry about producing a perfectly calibrated pain score.
Record headache-free days as well. Otherwise, a blank space could mean either that you felt well or that you forgot to write.
Add the effect on your day
A pain score cannot tell the whole story. Add one line about what you could or could not do: whether you left work early, lay down, canceled a plan or continued normal activities with difficulty.
Keep the wording descriptive. “Stopped reading because the light felt uncomfortable” communicates more than “bad afternoon.” You are giving your clinician context, not trying to prove that the headache was serious enough to deserve attention.
For illustration, an entry might say: “Tuesday, began around lunchtime; still present at dinner; rested in a quiet room; missed afternoon meeting.” This is a format example, not a pattern that identifies a particular diagnosis.
If someone helped you during the episode, they may remember a detail you missed. Make clear which observations came from them.
Keep a complete medicine record
Write down the product name, the amount you actually took and approximately when you took it. Include nonprescription products as well as prescribed treatments. Bring the packaging or a photograph of the label if names are confusing.
This is a record of use, not an instruction to change treatment. Do not increase doses, combine medicines or stop a prescribed medicine based on a pattern you think you see in the diary.
Discuss medicine use with your clinician or pharmacist, especially during pregnancy, with other medication or with existing health conditions. Ask them to check the full list and explain any instructions you are unsure about.
NICE includes medication-overuse headache in its assessment guidance. Honest records of how often you use headache treatments help that discussion; they are not a reason to feel embarrassed or to manage withdrawal on your own.
Treat possible triggers as questions
You may notice a headache after a stressful meeting or a different night's sleep. Write the observation without declaring the cause. “Slept less than usual” is a useful note; “sleep caused this headache” goes beyond what a single entry can establish.
Avoid adding so many categories that the diary becomes a second job. Start with the clinician's requested details and a small space for anything unusual. If a specific pattern emerges, bring it to the appointment.
Do not cut out broad groups of foods or reorganize every part of your day on the strength of a few entries. Several things can change together, and the record cannot separate them with certainty.
Turn the diary into a useful conversation
Before the appointment, make a brief summary: how many days included headache, how many included headache medicine, and which episodes most disrupted your routine. Keep the original entries available rather than replacing them with your interpretation.
Write down two or three questions. You might ask what further assessment is needed, what a treatment plan should look like and which changes mean you should seek help sooner.
Agree on when to review the plan and whether to keep recording. A diary is most useful when it supports a conversation and a next step. It should not become a task you continue indefinitely without knowing what you are using it for.
Photo: Pavel Danilyuk / Pexels.