Which condition often causes painful periods and heavy bleeding?

Endometriosis is a condition where tissue similar to the lining of the uterus grows outside the uterus, leading to various symptoms, including painful periods and heavy bleeding. The misplaced tissue responds to hormonal changes during the menstrual cycle, causing irritation, inflammation, and pain. This constant shedding can lead to heavier menstrual flow compared to a typical cycle.

The other conditions can also cause pelvic pain or hormonal imbalances, but they typically have different symptoms. Menstrual cramps, while they cause pain, are generally related to the contraction of the uterus and not associated with heavy bleeding. Fibroids, while they can lead to heavy and prolonged menstrual bleeding, may not always be accompanied by pain, as symptoms can vary widely among individuals. Ovarian cysts may cause pain, especially if they rupture, but they are less commonly associated with significant changes in menstrual bleeding patterns compared to endometriosis.