Hemicrania continua characterized by continuous pain for at least one year, without remission periods of at least 24 hours.

Diagnostic criteria:
  1. Headache fulfilling criteria for 3.4 Hemicrania continua, and criterion B below
  2. Headache is daily and continuous for at least 1 year, without remission periods of ≥24 hours.

3.4.2 Hemicrania continua, unremitting subtype can arise de novo or evolve from 3.4.1 Hemicrania continua, remitting subtype. The majority of patients have the unremitting subtype from onset.