DUB is defined as a state of abnormal uterine bleeding without any clinically detectable organic, systemic, and iatrogenic cause (Pelvic pathology, eg., tumor, inflammation or pregnancy is excluded) In this case, hormonal imbalance is considered the root cause of hyperplasia of the endometrium that causes menorrhagia; this often happens in anovulatory cycles with excessive or unopposed influence of oestrogen on the endometrium Ref: Shaw&;s textbook of Gynaecology 17th edition PGno: 132