What causes women to lose extensive amounts of blood during the menstruation period?

 
Passing of excessive blood during periods is known as Menorrhagia. The condition may be so severe in some women that they may even pass blood clots. There are several causes for menorrhagia. it can be due to fibroids, hormonal imbalance, excessive sensitivity of the uterine lining (endometrium) to hormones, endometrial polyps, infection etc. Endometrial cancer can also present as menorrhagia. Women suffering from menorrhagia should consult a gynaecologist to determine the cause. Only then can appropriate treatment be started.