Understanding patterns in your migraine diary
A trigger summary describes what you recorded. Learn what its percentages mean, why the date range matters and what a diary cannot establish on its own.
What a trigger percentage actually means
In Migraine Tracker, a trigger percentage is the share of recorded attacks in the selected period where you selected that item. It does not measure how likely something is to cause a future attack.
For example, the website’s fictional 90-day history contains 20 completed attacks. “Too Little Sleep” appears in 11 of those records, so the trigger summary shows 55%.
That means “logged in 11 out of 20 attacks.” It does not mean “a 55% chance of migraine after a short night.” The summary does not include every occasion on which the person slept poorly without recording an attack.
You can select more than one trigger or symptom in an entry, so the percentages do not need to add up to 100%. This is a description of the app’s sample data, not a finding about migraine in the wider population.
A pattern is not proof of a cause
Events appearing together in a diary can be worth discussing, but that alone does not show that one caused the other. What you noticed, what you remembered and what you chose to enter all affect the record.
There is another complication: The Migraine Trust explains that something interpreted as a trigger may sometimes be an early sign of an attack. Its guide to migraine attack triggers describes why identifying triggers can be difficult.
Use the summary as a way to form a question. You do not need to make a diagnosis or change treatment based on a bar chart. Our post on barometric pressure and migraine shows how to check one suspected trigger against your own records.
Compare like with like
Before comparing two views, check three things:
- The period. A 30-day report and a 90-day report cover different records. The website’s sample PDF uses 30 days; the trigger screenshot uses 90 days.
- What is being counted. Recorded attacks, headache days and medication days are different measures. A number labelled “days” should not be read as the number of medication doses or individual attacks. See how headache and migraine days are counted and how to count medication days.
- How complete the record is. A change in how often you logged entries can change a summary. An unrecorded day is not confirmed to be symptom-free.
The same caution applies to symptoms. A symptom appearing frequently in your entries tells you what you recorded, not how often it occurs in everyone with migraine.
Bring an observation, not a verdict
Try turning what you see into a concrete sentence: “I logged short sleep in several attacks this month. What would be useful to record next?”
That sentence separates the observation from its possible explanation. You can open the individual entries to add context that a summary cannot show, such as an estimated time or a note you made that day.
Migraine Tracker keeps the history and report together, so you can move between the overview and the underlying records. Our appointment checklist can help you prepare what to bring.
Sources
Sources checked on 28 September 2026. The arithmetic and examples refer to the app’s fictional demonstration history.
This is a record-keeping guide, not medical advice. The sources explain general principles and do not endorse Migraine Tracker.