Table 4 Classification of chronic migraine [2]

1.3 [G43.3] Chronic Migraine

 A. Headache (migraine-like or tension-type-like) on ≥15 days for > 3 months, and fulfilling criteria B and C

 B. Occurring in a patient who has had at least five attacks fulfilling criteria B-D for Migraine without aura and/or criteria B-C for Migraine with aura

 C. On ≥8 days/month for > 3 months, fulfilling any of the following:

  1. criteria C and D for Migraine without aura

  2. criteria B and C for Migraine with aura

  3. believed by the patient to be migraine at onset and relieved by a triptan or ergot derivate

 D. Not better accounted for by another ICDH-3 diagnosis