Principles & Practice of Pain Medicine > Part IV. Pain by Anatomic Location > A. Head and Neck > Chapter 19. Pathophysiology of Headaches F. Michael Cutrer and Amy O'Donnell

Pathophysiology of Headaches: Introduction

"Headaches are estimated to affect over 90% of the general population at some time in their lives¹ and may be encountered by physicians in a wide variety of clinical settings. The overwhelming majority of recurrent headaches occur in the context of what are known as primary headache disorders, in which no identifiable underlying cause can be found. Some headaches, however, classified as secondary headache disorders, are symptomatic of an underlying abnormality that may include anything from transient viral illness, to intracranial tumor, aneurysm, or drug withdrawal (for differential diagnosis of secondary headache disorder, see Cutrer²). Prevalence studies indicate that a benign process, such as a mild febrile illness or alcohol withdrawal, usually causes secondary headaches and that the lifetime prevalence of headache resulting from more ominous intracranial structural lesions is less than 2%.³..."