Heavy menstrual bleeding that lasts no more than 5 days, with usually more than 80ml of blood loss. One-third of women complain of heavy periods, although what constitutes heavy varies from woman to woman. The common symptom is blood gushing out that will soak sanitary towels very quickly, possibly leading to embarrassing leakage. A blood test can be taken to check blood coagulation factors and thyroid function, while an ultrasound can be performed to assess the thickness of the endometrial lining (greater than 10mm) or any possible masses such as polyps, fibroids or cysts that can rupture causing excessive blood loss. If the endometrial lining is greater than 10mm, a biopsy will be taken. Within western medicine, heavy menstrual bleeding can be caused by fibroids (in 30% of women) or polyps (in 10% of women). A small percentage of women have chronic pelvic infection or ovarian tumours. The other 58% are unknown.