Cyst rupture most commonly occurs in functional cysts. They can rupture either spontaneously or due to trauma (e.g. sexual intercourse or contact sport). Spontaneous rupture usually occurs on days 20–26 of the menstrual cycle. The size of the cyst and its contents will affect the severity of the symptoms with pain being much more severe in endometriotic or dermoid cyst rupture due to the contents irritating the peritoneum.