The main characteristic of endometriosis is painful menstruation, and in severe cases, it can lead to heavy periods and prolonged menstrual cycles. If endometriosis leads to the formation of ovarian chocolate cysts, the rupture of these cysts can cause severe abdominal pain. Moreover, endometriosis can easily lead to pelvic adhesions, which are a common cause of infertility. If the condition is severe, abdominal pain may also occur after the menstrual period has ended. In the case of adenomyosis, the symptoms include an enlarged uterine body, heavy periods, and prolonged menstrual cycles. If the condition is severe, then surgical treatment may be necessary.