What is the primary symptom of endometriosis?

The primary symptom of endometriosis is severe pain during menstruation, often referred to as dysmenorrhea. This pain can be much more intense than typical menstrual cramps, and it may occur before the menstrual period begins, throughout the period, and even in the weeks between periods. This pain arises because endometrial tissue, which normally lines the inside of the uterus, can grow outside of the uterus and irritate surrounding tissues. In some cases, this condition can also lead to chronic pelvic pain.

While other symptoms can occur with endometriosis, such as increased menstrual flow or vaginal dryness, they are not considered the primary or most characteristic symptom of the condition.