During your menstrual cycle, if an egg is not fertilized, the uterine lining breaks down, and bleeds. The egg and the uterine lining are then shed during your period.
Hormone problems or conditions that affect the uterus can result in heavy bleeding. Other diseases or bleeding disorders can also cause it.
Hormone problems include:
- An imbalance of estrogen and progesterone or other hormones.
Problems with the uterus include:
- Fibroids (noncancerous) or endometrial polyps.
- Cancer.
- Pregnancy problems (such as a miscarriage or ectopic pregnancy).
- The use of an intrauterine device.
Other conditions, such as thyroid, kidney or liver disease, cancer, or bleeding disorders, can also cause heavy bleeding.