A. Any headache fulfilling criteria C and D
B. Traumatic injury to the head has occurred, associated with at least one of the following:
1. loss of consciousness for >30 min
2. Glasgow Coma Scale (GCS) <13 3. post-traumatic amnesia lasting >24 hr
4. alteration in level of awareness for >24 hr
5. imaging evidence of a traumatic head injury such as intracranial haemorrhage and/or brain contusion.
C. Time of onset of headache is uncertain, and/or headache is reported to have developed >7 days after all of the following:
1. the head injury
2. regaining of consciousness following the head injury (when applicable)
3. discontinuation of medication(s) that impair ability to sense or report headache following the head injury (when applicable)
D. Headache persists for >3 months after the head injury
E. Not better accounted for by another ICHD-3 diagnosis.