How many migraine days is chronic migraine?
Chronic migraine has a specific definition: 15 or more headache days a month for more than three months, on at least 8 of which the headache has migraine features. Fewer than 15 headache days a month is classed as episodic migraine. The distinction is a clinical one — this page explains the criteria so you can track the right thing.
The ICHD-3 definition
The International Classification of Headache Disorders (ICHD-3) sets the standard. Chronic migraine means headache on 15 or more days per month for more than three months, where on at least 8 of those days the headache meets the criteria for migraine (or responds to migraine-specific treatment). It's a threshold that captures a genuinely different burden of illness, not just 'a lot of headaches'. Note the 'more than three months' part — a single heavy month doesn't make migraine chronic.
Why the count is easy to get wrong
Fifteen days sounds precise, but almost nobody can reconstruct it accurately from memory, and the difference between 12 and 16 headache days a month is exactly the difference the definition turns on. Milder headache days blur together and get forgotten, which usually leads to under-counting. That's why the definition is built around a monthly tally rather than an impression — and why a dated record is the only reliable way to know where you sit.
How tracking helps
Logging every headache day, with a note of whether it had migraine features, gives you a real monthly count to bring to a clinician — the same count the definition uses. It also shows the trend over several months, which matters because the criteria depend on time. Temple keeps that tally; it records the pattern and doesn't diagnose or label your migraine for you. Temple is a tracking tool, not medical advice — for anything specific to you, consult a healthcare professional.
Temple keeps an accurate monthly count of headache and migraine days, so the 15-day line the definition turns on is something you can actually see.
Common questions
- Is 15 headache days a month always chronic migraine?
- The ICHD-3 definition is 15 or more headache days a month for more than three months, with at least 8 showing migraine features. The 'more than three months' condition matters, so a single busy month doesn't qualify. Whether the criteria are met is a clinical judgement based on your record.
- What counts as a headache day?
- For this count, a headache day is any day you had a headache, not only full-blown migraine attacks — with a subset of at least 8 needing migraine features. Because milder days are easy to forget, a dated diary gives a far more accurate monthly total than memory.