Abstract: This paper reviews the literature of genetic epidemiology in primary headaches. Migraine without aura and migraine with aura are distinct disorders. Both are caused by a combination of genetic and environmental factors. Tension–type headache. The episodic form is most likely non–genetic, while the chronic form is caused by a combination of genetic and environmental factors. Cluster headache has previously not been thought to be genetic. However, first degree relatives of cluster headache sufferers have a 14–46 fold significantly increased risk of cluster headache, compared to the general population.