title: Dangerous and thunderclap headaches.
abstract: The International Classification of Headache Disorders-II considers dangerous and thunderclap headaches as secondary headaches--in other words due to an underlying cause. Many, but not all of the underlying etiologies, are vascular disorders, and many are potentially life threatening. An especially comprehensive clinical approach is necessary when seeing patients with these potential disorders.
authors.affiliation: Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: R Allan
authors.initials: RA
authors.lastname: Purdy
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Ward
mesh_terms: D003937:Diagnosis, Differential; D051270:Headache Disorders, Primary / Q000175:diagnosis* / Q000209:etiology; D051271:Headache Disorders, Secondary / Q000175:diagnosis* / Q000209:etiology; D006801:Humans