This study was designed to document prospectively and explore scientifically the natural course of untreated migraine attacks in detail. A new, integrated, time-intensity method for self-assessment of the intensity of symptoms was tested on 18 adult International Headache Society migraineurs who volunteered to refrain from treatment during one attack. The area under the curves (AUC) during 72 h of untreated attacks was compared with attacks treated with a triptan. Migraine attacks are heterogeneous both inter- and intra-individually. In untreated attacks, the pain can stabilize and fluctuate around a plateau with a wavelength of hours. In general, the symptoms of each separate migraine attack follow a similar temporal course, with only moderate deviations. In some cases photo- and/or phonophobia (hyperexcitability) were not experienced at all, despite severe pain and nausea. Moreover, there was sometimes no nausea despite severe pain and hyperexcitability. Vomiting does not always correlate to the intensity of nausea and is not always followed by decreased headache intensity. Treatment with a triptan usually only temporarily distorts the basic pattern of attacks. Hyperexcitability can respond before pain to treatment. These genuine findings of the classic symptoms of migraine attacks support the notion of a mutual underlying pathophysiological mechanism.