Menstrual Disorders - Causes

Causes

Dysmenorrhea

• Contraction-Causing Chemicals. Powerful chemicals known as prostaglandins and arachidonic acid can induce uterine muscle contractions. Prostaglandins also play a large role in the heavy bleeding that causes dysmenorrhea.
• Abnormal Nervous System Response. Some women with primary dysmenorrhea may have autonomic nervous systems that are overly sensitive to menstrual cycle changes. The autonomic nervous system regulates heart rate and blood pressure, and it contains the pain receptors in nerve fibers in the uterus and pelvic area. As a result, women with autonomic nervous system abnormalities may have a more intense response to pain.
• Abnormalities in the Arteries in the Uterus. Impaired blood flow through the arteries in the uterus may cause severe dysmenorrhea for some women.
• Genetic Factors. Genetic factors may play a role in primary dysmenorrhea cases.
• Endometriosis. Endometriosis is a chronic and often progressive disease that develops when the tissue that lines the uterus (endometrium) grows onto other areas, such as the ovaries, bowels, or bladder. It often causes chronic pelvic pain. [For more information, see In-Depth Report #74: Endometriosis.]

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• Uterine Fibroids. Fibroids are noncancerous growths that grow on the walls of the uterus. They can cause heavy bleeding during menstruation and cramping pain. [For more information, see In-Depth Report #73: Uterine fibroids.]
• Other Causes. Pelvic inflammatory disease, ovarian cysts, and ectopic pregnancy. The intrauterine device (IUD) contraceptive can also cause dysmenorrhea.

Abnormal Uterine Bleeding

Abnormal uterine bleeding may occur as infrequent episodes, excessive flow, prolonged duration of menses, or bleeding between menses.

Examples of abnormal bleeding include:

• Bleeding or spotting between periods
• Bleeding after sex
• Bleeding heavier or for more days than normal
• Bleeding after menopause