The characteristics of common migraine are not unique, they also appear in other forms of benign headaches. As there are no laboratory tests and biological signs enabling the diagnosis of migraine and its differentiation from the headache due to muscle contractrion, clinical criteria which are simplified and easy to comprehend should be used. We compared the symptoms in 29 patients of both sexes, suffering from common migraine, as well as 29 patients with headache due to muscle contraction (chronic daily headaches). In common migraine the following symptoms appear in greater percentage (statistically significant): nausea, vomiting, unilateral localization of pain, pulsating pain, photophobia and phonophobia. Bad headache is more frequent in patients with common migraine than in those suffering from chronic headache. We should accept Solomon's and Cappa's attitude who suggest at least two of the following five criteria: 1. nausea with or without vomiting, 2. unilaterality, 3. pulsating pain, 4. photophobia or phonophobia, and 5. provocation by menstruation or positive family history. Besides the above mentioned criteria the authors also mention and emphasize the existence of free interval in migraine when the patient has no difficulties and feels well.