In the last podcast we discussed tension-type headache. In the current podcast, we discuss cluster headache, which is a rare variety of primary headache, having a population frequency of about 0.1%. Because the pain of cluster headache is one of the most severe that humans experience, the treatment of cluster headache often becomes almost an emergency as patients seek relief. To discuss cluster headache diagnosis and treatment, we have Dr. Werner Becker back with us once more. Dr. Becker is a Professor of Neurology at the University of Calgary and a fellow of the American Headache Society. He has also recently written a clinical review entitled “Cluster Headache: Conventional Pharmacological Management” in the journal Headache (2013; 53(7); 1191-1196). The content of the current podcast is largely based on this article.