In some cases, the cause of heavy menstrual bleeding is unknown, but a number of conditions may cause menorrhagia.
Common causes include:
In a normal menstrual cycle, a balance between the hormones estrogen and progesterone regulates the buildup of the lining of the uterus (endometrium), which is shed during menstruation. If a hormone imbalance occurs, the endometrium develops in excess and eventually sheds by way of heavy menstrual bleeding.
A number of conditions can cause hormone imbalances, including polycystic ovary syndrome (PCOS), obesity, insulin resistance and thyroid problems.
Dysfunction of the Ovaries
If your ovaries don’t release an egg (ovulate) during a menstrual cycle (anovulation), your body doesn’t produce the hormone progesterone, as it would during a normal menstrual cycle. This leads to hormone imbalance and may result in menorrhagia.
These noncancerous (benign) tumors of the uterus appear during your childbearing years. Uterine fibroids may cause heavier than normal or prolonged menstrual bleeding.
Polyps. Small, benign growths on the lining of the uterus (uterine polyps) may cause heavy or prolonged menstrual bleeding.
This condition occurs when glands from the endometrium become embedded in the uterine muscle, often causing heavy bleeding and painful periods.
Intrauterine Device (IUD)
Menorrhagia is a well-known side effect of using a nonhormonal intrauterine device for birth control. Your doctor will help you plan for alternative management options.
Pregnancy complications. A single, heavy, late period may be due to a miscarriage. Another cause of heavy bleeding during pregnancy includes an unusual location of the placenta, such as a low-lying placenta or placenta previa.
Uterine cancer and cervical cancer can cause excessive menstrual bleeding, especially if you are postmenopausal or have had an abnormal Pap test in the past.
Inherited Bleeding Disorders
Some bleeding disorders — such as von Willebrand’s disease, a condition in which an important blood-clotting factor is deficient or impaired — can cause abnormal menstrual bleeding.
Certain medications, including anti-inflammatory medications, hormonal medications such as estrogen and progestins, and anticoagulants such as warfarin (Coumadin, Jantoven) or enoxaparin (Lovenox), can contribute to heavy or prolonged menstrual bleeding.
Other medical conditions. A number of other medical conditions, including liver or kidney disease, may be associated with menorrhagia.