Menstrual disorders are problems related to a woman’s menstrual cycle. They are among the most common conditions in women. Many menstrual disorders are not a cause for concern, but others require a physician consultation.

Menstruation is the discharge of blood and tissue that occurs each month as part of a woman’s menstrual cycle. The cycle can vary from 21 to 42 days in length, although the average length is 28 days. This cycle is controlled by hormones produced in certain parts of the brain and the ovaries to prepare the reproductive organs for pregnancy. The lining of the uterus (endometrium) thickens in response to the hormones. If pregnancy does not occur, the lining begins to break down and discharges from the body through the vagina as the menstrual period.

Menstruation begins on average when a girl is about 12 or 13 years old (puberty) and continues monthly until menopause occurs many years later. These are considered a woman’s reproductive years and indicate the woman is physically able to become pregnant. Menstrual periods usually occur once a month and last for several days during each month. A missed menstrual period is frequently the first sign that pregnancy has occurred. The uterine lining is not shed, but rather will grow during pregnancy and provide an area for growth of the placenta (a temporary organ that provides nourishment for the developing fetus). 

As a woman ages and hormone levels slowly begin to decrease, the menstrual cycle eventually ends (menopause). Menopause typically occurs during a woman’s early 50s but it may occur earlier or later in life.

Menstrual disorders occur when certain factors interrupt the hormones that control menstruation. Common disorders include:

• Missed periods
• Periods that are unusually heavy or light
• Periods that are unusually long
• Unusually infrequent periods
• Unusually painful periods

These disorders can be temporary or permanent. In addition, many women experience some variation in menstrual cycle symptoms from one month to the next, especially during the first years after the beginning of menstruation (menarche). Some disorders may interfere with a woman’s ability to participate in everyday activities, attend work or school and sleep. Certain menstrual disorders may also interfere with a woman’s ability to become pregnant.