What is considered normal menstruation?

Menstruation is the discharge of blood and tissue that occurs each month as part of a woman's menstrual cycle. It usually begins when a girl is about 12 or 13 years old (puberty) and continues until menopause (typically in a woman's early 50s).

Menstrual periods usually occur once a month and last for several days during each month. Cycle length varies by the woman, but it averages about 28 days. The blood flow of menstruation may vary from month to month and from woman to woman.

Before and during menstruation, women may experience some mild to moderate cramps, water retention and irritability. Abnormally heavy blood flow, irregular cycle length or severe premenstrual syndrome (PMS) symptoms may indicate a menstrual disorder.

What are common menstrual disorders?

Menstrual disorders involve periods that are unusually:

• Heavy or long (menorrhagia)
• Light (hypomenorrhea)
• Frequent (polymenorrhea)
• Infrequent (oligomenorrhea)
• Painful (dysmenorrhea)

Amenorrhea (lack of menstruation) may also be considered a menstrual disorder, depending on the circumstances. Primary amenorrhea refers to girls who have not experienced their first periods and is considered normal until the typical age of puberty is passed. A girl who has not had her first period by age 16 should consult her physician. Secondary amenorrhea refers to someone who has menstruated previously but has stopped.


Is PMS considered a menstrual disorder?


Yes. Most women experience some symptoms of PMS including irritability, mood swings, anxiety, depressed mood, appetite changes, fluid retention and fatigue. Menstrual cramps are not considered a PMS symptom. The exact cause of PMS is not known.

Up to 40 percent of menstruating women have PMS symptoms severe enough to require treatment according to National Women's Health Resource Center. Between 3 and 8 percent of women experience a related, but more serious, condition called premenstrual dysphoric disorder (PMDD).


What causes menstrual disorders?

The most common causes of menstrual disorders are: