[Different headache forms of chapter 4 of the International Headache Classification]

Chapter 4 of the International Classification of Headaches contains a group of clinically very heterogeneous primary headache forms. Little is known about the pathogenesis of these headache types and therapy is usually based on isolated case reports and uncontrolled studies. The forms include primary stabbing headache, primary cough headache, primary exertional headache, primary headache associated with sexual activity, hypnic headache, primary thunderclap headache, hemicrania continua and the new daily persistent headache. Some of these headache forms may be of a symptomatic nature and require careful examination, imaging and further tests. Primary and secondary headache forms must be carefully distinguished.