Migraine trigger factors

Abstract

In second-century Rome Galen of Pergamon suggested that migraine was triggered by yellow bile irritating the brain and meninges. Today atmospheric, nutritional, hormonal, physiological, and pharmacological triggers have been investigated in numerous clinical studies. A trigger for migraine is any factor that upon exposure or withdrawal can lead to the development of a migraine attack. According to the International Headache Society, trigger factors increase the probability of a migraine attack usually within 48 hours. Thus, a trigger factor is not regarded as a necessary causative agent in migraine, and therefore the presence of a trigger factor may not always induce an attack. The majority of studies on trigger factors are retrospective surveys hampered by recall bias, multiple significance errors, and questionnaire design, which may explain differences between studies. There are only a limited number of prospective studies, with conflicting results. In this chapter the present knowledge on migraine triggers is presented and described, highlighting both facts and myths. In addition, we will discuss the clinical implications of identifying triggers, and whether there is any rationale for avoidance of triggers, which has been a classic strategy, and recommendation for migraine treatment.