Cluster headache: are we only seeing the tip of the iceberg?
D000328:Adult; D003027:Cluster Headache / Q000175:diagnosis* / Q000209:etiology / Q000235:genetics; D003937:Diagnosis, Differential; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D008297:Male; D008881:Migraine Disorders / Q000175:diagnosis; D014653:Vascular Headaches / Q000175:diagnosis*