How to keep a headache diary your doctor can use

What to record for each headache

NICE's guideline on headaches in people over 12 suggests that, when a diary is used to help diagnosis, it records for a minimum of eight weeks:

• the frequency, duration and severity of headaches;
• any associated symptoms;
• all prescribed and over-the-counter medicines taken to relieve headaches;
• possible precipitants;
• the relationship of headaches to menstruation.

The Japanese Headache Society's diary asks for much the same in more concrete terms: the date and time, what the pain felt like (throbbing or tight, for example), how long it lasted, whether nausea or light, sound or smells bothered you, what you took and whether it worked, how much the headache disrupted your day, and a free note for anything you noticed beforehand, such as an event, a trip, the weather or oversleeping.

In practice, a good entry fits on one line: Tue 07:10, left-sided throbbing, 7/10, nausea, light hurt, ibuprofen 08:00 helped partly, gone by 15:00, short sleep, rain all day.

How long to keep it going

Eight weeks is the minimum NICE gives. It is long enough to count headache days per month with some confidence and to catch a few weather changes, busy weeks and quiet ones. If your headaches seem tied to your period, NICE suggests diagnosing menstrual-related migraine from a diary covering at least two menstrual cycles.

Frequency matters for diagnosis. In NICE's table, chronic migraine means headache on 15 or more days a month for more than three months, with at least eight of those days having features of migraine. You cannot tell 12 days a month from 16 from memory; a diary can.

Once you have a diagnosis and a treatment plan, a diary keeps its value: NICE also suggests using one to monitor how well treatment is working.

Count your medication days

The most useful single number in many diaries is the count of days on which you took something for a headache. NICE advises clinicians to consider medication overuse headache when headaches have developed or worsened in someone taking triptans, opioids, ergots or combination painkillers on 10 or more days a month, or paracetamol, aspirin or an NSAID, alone or in any combination, on 15 or more days a month, for three months or more.

So record every dose, including the ones that “don't count” because they were small or for something else, and total the days at the end of each month. If you are near those numbers, tell your doctor rather than cutting back abruptly on your own.

Make it easy enough to keep

Diaries fail because they get skipped, not because they lack detail. A few habits help:

• Log at onset, finish later. Record the start time and severity as soon as you can, and add the rest when you feel better.
• Back-date honestly. If you remember a headache the next morning, add it with its real start time rather than leaving a gap.
• Log mild ones too. A diary of only severe attacks makes headache-free days look more common than they are.
• Use the same severity scale every time. A 0–10 or 1–10 scale works; the Japanese Headache Society uses mild, moderate and severe. Consistency matters more than the scale.
• Mark headache-free days if you can. The German Migraine and Headache Society's diary app, for example, reminds people once a day to make an entry and asks for details only on days with a headache.

Possible factors: note them, then test them

It is natural to look back at a headache and find something that happened before it. The trouble is that something always happened before it. A review by Hoffmann and Recober points out the substantial gap between the factors patients report and what controlled studies have been able to confirm, and why that relationship is so hard to study.

A diary helps you test a suspicion instead of just confirming it. For any factor, ask two questions: how often did it come before a headache, and how often does it happen anyway? If big pressure changes happen around a third of the time where you live, a third of your headaches following one is what chance would give you. More than that is worth discussing; about the same suggests looking elsewhere.

Keep the list of factors short. Two or three things you genuinely suspect, such as sleep, alcohol or the weather, are more useful than twenty boxes you tick from habit.

Paper, spreadsheet or app?

Whichever you will keep using. Paper diaries work well; the Japanese Headache Society publishes a printable one covering four weeks per sheet, split into morning, afternoon and night. Apps add timestamps, reminders and exports. A spreadsheet is easy to total but easy to forget.

If you use an app, check two things: that you can get your data out in a form a doctor can read, and where the data is stored. A health diary is personal; an app that keeps it on your phone and lets you export it yourself gives you control over who sees it.

Turning eight weeks into one page

Your doctor may have ten minutes. Bring the full diary, but lead with a summary like this:

Add one or two sentences on what you want from the visit, for example a diagnosis, a review of what to take for attacks, or whether the medication days are a concern.