Repeated headache attacks lasting 4-72 h fulfilling at least two of the following criteria: 1) unilateral location, 2) pulsating quality, 3) moderate or severe pain intensity, and 4) aggravation by or causing avoidance of routine physical activity such as climbing stairs. Headache attacks are commonly accompanied by nausea, vomiting, photophobia, or phonophobia. The definition of this term is based on the definition in the International Classification of Headache Disorders by the International Headache Society (pmid:15304572), which additionally stipulate that such headaches must have occurred at least five times and not other secondary cause must be apparent in order to make the diagnosis.