Headache is among the most common medical complaints. An overview of the approach to the patient with headache is presented here. The approach to adults presenting with headache in the emergency department is reviewed elsewhere. (See "Evaluation of the adult with headache in the emergency department".)
The clinical features and management of specific primary headache syndromes are discussed separately. (See "Pathophysiology, clinical manifestations, and diagnosis of migraine in adults" and "Tension-type headache in adults: Pathophysiology, clinical features, and diagnosis" and "Cluster headache: Epidemiology, clinical features, and diagnosis".)
EPIDEMIOLOGY AND CLASSIFICATION OF HEADACHE
As many as 90 percent of all benign headaches fall under a few categories, including migraine, tension-type, and cluster headache. While a population-based study found that the one-year prevalence of episodic tension-type headache was 38 percent , most of these people do not present to physicians for care. As an example, a study of two primary care units in Brazil found that migraine was the most prevalent primary headache disorder, accounting for 45 percent of patients reporting headache as a single symptom .
Cluster headache typically leads to significant disability and most of these patients will come to medical attention. However, cluster headache remains an uncommon diagnosis in primary care settings because of overall low prevalence in the general population (<1 percent). (See "Cluster headache: Epidemiology, clinical features, and diagnosis", section on 'Epidemiology'.)
Clinicians can easily become familiar with the most common headache disorders and how to differentiate between them (table 1). It is not necessary to follow the detailed classification and diagnostic criteria proposed by the International Headache Society (IHS), although there are certain important points that should be kept in mind whenever describing, managing, or discussing patients with headache: