Hemicrania continua and paroxysmal hemicrania are considered different headaches belonging to a group of trigeminal autonomic cephalalgias. However, they share many clinical features. Both headaches also show complete response to indomethacin, which is a mandatory criterion for their diagnosis. Are they really different headaches? To answer this question, we compared the pain characteristics and autonomic features between two headaches. We also determined whether paroxysmal hemicrania transforms into hemicrania continua or vice versa in their natural history.