This is the part of a headache diary people are most often surprised by, and it is the easiest of the three numbers to collect: how many days in a month did you take something for a headache?
Days, not doses. Two tablets on a Tuesday is one treatment day. It is a deliberately blunt measure, and it is blunt because that is how the thresholds are written.
What medication-overuse headache is
The ICHD-3 recognises medication-overuse headache: headache occurring on 15 or more days per month in someone with a pre-existing headache disorder, developing as a consequence of regular overuse of acute or symptomatic headache medication for more than three months.
The uncomfortable part is the mechanism it implies. The medication that helps an individual attack can, taken often enough over long enough, become part of why the attacks keep coming. This is not a moral failing and it is not rare; it is a recognised and well-described complication of treating a condition that keeps recurring.
The thresholds, and why they differ
The ICHD-3 sets different limits for different classes of acute medication:
| Acute medication | Regular use on |
|---|---|
| Triptans | 10 or more days a month |
| Ergotamine | 10 or more days a month |
| Opioids | 10 or more days a month |
| Combination analgesics | 10 or more days a month |
| Simple analgesics — paracetamol / acetaminophen, aspirin, other NSAIDs | 15 or more days a month |
| Multiple classes together, none individually over its own limit | 10 or more days a month |
Two things in that table catch people out. The first is that the last row exists at all: alternating between two or three things does not reset the count, and the combined limit is the lower one. The second is that over-the-counter combination painkillers sit in the 10-day row, not the 15-day row — they are the ones most likely to be taken without anyone thinking of it as medication at all.
All of these are thresholds for regular use over more than three months. One bad month is not the thing being described.
Why it creeps up
Because no individual month feels like a problem. Eight treatment days in a month with a deadline is a reasonable response to a bad month. Eight again because of a cold. Nine over the holidays. Each decision is defensible; the only thing that reveals the pattern is a count kept across months, which is precisely what nobody has when the question is asked in an appointment.
It is also the number people under-report, usually without meaning to. Over-the-counter tablets taken at work do not feel like an event worth remembering.
What to do with the number
Bring it to a clinician. That is the whole of the advice this page will give, and the reason for the limit is specific rather than legal caution: stopping an acute medication abruptly on your own can make things worse before they get better, and how to approach it depends on which medication, for how long, at what dose, and what else is available to you during it. Some withdrawals want a preventive treatment started first; some want supervision. None of that is a decision to make from a web page.
What you can do without anyone's help is count honestly. Log every day you take something for your head, including the tablets that do not feel worth logging. If the count is under the thresholds, you have removed a question. If it is over them, you have brought your clinician the most useful single figure in the diary.
Sources
- Headache Classification Committee of the International Headache Society. The International Classification of Headache Disorders, 3rd edition (ICHD-3). Cephalalgia 2018;38(1):1–211. ichd-3.org
Written in house and checked against the ICHD-3. Where this page describes the state of the evidence rather than a specific finding, it says so, and it cites nothing it cannot point at. A named clinical reviewer is to be appointed before launch. Found an error? Tell us and we will correct it on the page.
