Definition and causes of heavy menstrual bleeding

Heavy menstrual bleeding (menorrhagia) is excessive menstrual bleeding that interferes with physical, emotional, social and material quality of life; it can occur alone or with other symptoms. It does not include other types of abnormal uterine bleeding such as intermenstrual bleeding and postcoital bleeding.

Note: Heavy menstrual bleeding refers to heavy cyclical bleeding. Intermenstrual and postcoital bleeding require separate investigation and management.

Pregnancy-related bleeding must be excluded before considering other causes.

Causes of heavy menstrual bleeding in nonpregnant individuals include:

  • uterine pathology—adenomyosis, leiomyomas (fibroids), malignancy or hyperplasia
  • functional causes—primary disorders of endometrial haemostasis, coagulopathy, ovulatory dysfunction, iatrogenic and some that are yet to be classified.

Fibroids are the most common uterine pathology; they affect 30% of individuals who have heavy menstrual bleeding. Abnormal haemostasis within the endometrium (excess local fibrinolysis or prostaglandin production) is the most common functional cause of heavy menstrual bleeding but is a diagnosis of exclusion. Coagulopathy, such as von Willebrand disease, can cause heavy periods from menarche. Ovulatory dysfunction is most often due to polycystic ovary syndrome but other causes include hypothyroidism. Iatrogenic factors include intrauterine contraceptive devices, anticoagulant therapy, tamoxifen, and hormonal therapies with exogenous estrogens. Occasionally herbal supplements (eg ginseng, ginkgo, soya) are also implicated as they can alter estrogen levels or coagulation parameters.

Patient information about heavy menstrual bleeding is available from: