Hello Dear,
There could be several causes for prolonged bleedong like-
Hormonal imbalance, Uterine fibroids may cause heavier than normal or prolonged menstrual bleeding cause of
menorrhagia.
Polyps of the uterus most commonly occur in women of reproductive age as the result of high hormone levels
Uterine polyps may cause heavy or prolonged menstrual bleeding. s.
Lack of ovulation (anovulation) may cause hormonal imbalance and result in menorrhagia.
Adenomyosis- often causing heavy bleeding and pain. Adenomyosis is most likely to develop if you're a
middle-aged woman who has had many children.
Pregnancy complications. A single, heavy, late period may be due to a miscarriage. If bleeding occurs at the
usual time of menstruation, however, miscarriage is unlikely to be the cause. An ectopic pregnancy —
implantation of a fertilized egg within the fallopian tube instead of the uterus — also may cause menorrhagia.
Medications. Certain drugs, including anti-inflammatory medications and anticoagulants (to prevent blood
clots), can contribute to heavy or prolonged menstrual bleeding.
Other medical conditions. A number of other medical conditions, including pelvic inflammatory disease (PID),
thyroid problems, endometriosis, and liver or kidney disease, may cause menorrhagia..
You should consult a gynaecologist and go for ultrasonography and other investigations to diagnose the cause
,so that the treatment can be started.
Refer
http://www.mayoclinic.com/health/menorrhagia/DS00394/DSECTION=causes
for more info.
Best
