ABSTRACT
Headache, like back pain or abdominal pain, is a symptom that can have many causes. Since a range of disorders can produce headache, a systematic approach to headache classification and diagnosis is an essential prelude to its management and treatment. In 1988, the International Headache Society (IHS) instituted a classification system that has become the standard for headache diagnosis, particularly for clinical research. For the primary headache disorders, the IHS criteria provide a descriptive system that classifies headaches based on their symptom profiles. Because many headaches follow typical pain patterns, pain localization at onset and the pattern of spread assist diagnosis. Pain severity and the rapidity of onset and resolution are important diagnostic clues. Migraine pain is characteristically throbbing or pulsatile, but it often begins as a dull, steady ache that slowly evolves; it may not acquire a throbbing quality until the pain becomes moderate or severe in intensity.
