Menstrual disorders occur when certain factors interrupt a woman’s menstrual cycle. In normal function, the menstrual cycle lasts from 21 to 42 days. It includes the growth of the uterine lining, (endometrium) and its shedding during menstruation. Hormones in the brain and the ovaries control the menstrual cycle in women in their reproductive years.

Many disruptions and disorders can affect the menstrual cycle. Pregnancy is one of the most common. When a woman becomes pregnant, her menstrual cycle is disrupted because the uterine lining remains to provide a place for the fertilized egg to implant and grow. Menstrual disorders can also affect menstruation. These disorders can be temporary or permanent and may have an effect on the patient’s fertility.

Common menstrual disorders include missed periods (amenorrhea), as well as periods that are unusually heavy or long (menorrhagia), unusually light (hypomenorrhea), unusually frequent (polymenorrhea), unusually infrequent (oligomenorrhea) and unusually painful (dysmenorrhea).

Menstrual disorders can be caused by a wide variety of conditions and diseases. Common causes include failure of the ovary to release an egg (anovulation), polycystic ovarian syndrome (PCOS), endometriosis, pelvic inflammatory disease (PID), pregnancy complications, cancer, and uterine disorders such as polyps or fibroids. Pregnancy is the most common cause of a missed period.

Physicians may use laboratory tests and imaging tests, review the patient’s medical history and perform a physical examination to help determine the underlying cause of a menstrual disorder. After the cause is determined, the physician can choose the best course of treatment, if necessary. Treatment for menstrual disorders may include lifestyle changes (e.g., dietary habits, exercise) or medications. If these options fail to alleviate the problem, surgery (e.g., dilation and curettage, endometrial ablation or resection) may be recommended in some cases.

Some of these underlying causes can have long-term health consequences for the patient. As a result, it is important for women to report all menstrual disorders to their gynecologist (GYN). In addition, young women who have not had their first period by the age of 16 years are urged to contact a GYN. Young women who have not achieved a regular period after three years of menstruating should also consult a physician. Postmenopausal women who are experiencing vaginal bleeding of any form should consult their physician as well.

Although many of the underlying causes of menstrual disorders cannot be prevented, women can reduce the risk of some disorders by maintaining a healthy lifestyle, including eating a balanced diet and getting regular exercise.