Narendra Pisal, consultant gynaecologist at London Gynaecology, says adenomyosis occurs when the tissue that normally lines the uterus grows into the muscular wall of the uterus. During menstruation, the displaced tissue acts normally and thickens, breaks down, and bleeds. This causes an enlarged uterus and painful, heavy periods.
This is a companion discussion topic for the original article at https://patient.info/news-and-features/is-adenomyosis-the-cause-of-your-heavy-painful-periods