A peculiarity of endometriosis is that women with mild disease may have the worst symptoms and women with severe disease occasionally have none. Painful periods, dysmenorrhoea, may be a symptom of endometriosis. Increasingly painful periods or severe pain in the days leading up to a period should be viewed as a possible warning sign of endometriosis. However there are many women who suffer from painful periods who do not have endometriosis. Teenagers commonly complain of painful periods, but endometriosis is uncommon in this age group.
Endometriosis can cause pain during intercourse, a condition called dyspareunia.
The thrusting motion can cause pain in a tender nodule of endometriosis. Women with endometriosis can have irregular vaginal bleeding. These implants may bleed into the bladder or bowel during a period, causing blood stained urine or motions at the time of a period. The diagnosis of endometriosis cannot be made from symptoms alone since some women with endometriosis have no symptoms at all. A doctor may suspect the disease if a woman is having difficulty getting pregnant, or she has painful periods or pain during intercourse.