More IHS Resources

The International Headache Society (IHS) is the world's membership organisation for all whose professional commitment, whatever their discipline, is to helping people whose lives are affected by headache disorders.Visit the IHS website

Revised International Headache Society criteria for chronic migraine

  1. Headache (tension-type and/or migraine) on ≥15 days per month for at least 3 months*
  2. Occurring in a patient who has had at least five attacks fulfilling criteria for 1.1 Migraine without aura
  3. On ≥8 days per month for at least 3 months headache has fulfilled C1 and/or C2 below, that is, has fulfilled criteria for pain and associated symptoms of migraine without aura
    1) Has at least two of a-d
        a) unilateral location
        b) pulsating quality
        c) moderate or severe pain intensity
        d) aggravation by or causing avoidance of routine physical activity
            (e.g. walking or climbing stairs)
    and at least one of a or b
        a) nausea and/or vomiting
        b) photophobia and phonophobia
    2) Treated and relieved by triptan(s) or ergot before the expected development of C1 above
  4. No medication overuse† and not attributed to another causative disorder‡

* Characterization of frequently recurring headache generally requires a headache diary to record information on pain and associated symptoms day-by-day for at least 1 month. Sample diaries are available at

† Medication overuse as defined under 8.2 Medication-overuse headache.

‡ History and physical and neurological examinations do not suggest any of the disorders listed in groups 5–12, or history and/or physical and/or neurological examinations do suggest such a disorder but it is ruled out by appropriate investigations, or such disorder is present but headache does not develop in close temporal relation to the disorder.