Menstrual Disorders Amenorrhea

Amenorrhea is not the same as missing a period. A number of things may cause late menstrual periods or missing one entirely. For instance, if you’ve just reached puberty and have recently begun menstruating, having late menstrual periods is common.

The most common reasons for missed periods include:

  • pregnancy
  • inadequate nutrition
  • excessive exercise or physical stress, including international air travel
  • emotional stress
  • various illnesses.

Amenorrhea means the absence of menstruation and is different from late or delayed menstruation. Doctors usually use this term to refer to a woman who is at least sixteen years old and has never menstruated (primary) or to a woman has previously had periods but later stopped (secondary amenorrhea). Secondary amenorrhea is not the same as menopause, the time when a woman’s body stops ovulating (producing eggs) and menstruation stops.

What is Secondary Amenorrhea?

About four percent of women experience secondary amenorrhea, which refers to a condition in women who started menstruating at the appropriate age, but whose menses have stopped for either three consecutive menstrual cycles or a total six months or more.

Other causes of missed periods include:

  • approaching menopause
  • breastfeeding
  • extreme weight loss (body fat less than seventeen percent)
  • pituitary, thyroid, or adrenal gland dysfunction.
  • contraceptives, anabolic steroids and certain medications
  • thyroid imbalance
  • ovarian cysts
  • ovarian failure.

Infrequent Menstruation: Oligomenorrhea

When a woman has infrequent periods, she is said to have oligomenorrhea (after the Greek word oligo, for “scant”). Doctors use the term oligomenorrhea when a woman who has had a normal cycle suddenly begins to cycle every 35 days or more, and only has four to nine periods in a year.

Diagnosis and Treatment of Amenorrhea

If you have missed more than one period or are concerned about delayed menstruation or bleeding, consult your physician.

A pelvic exam, physical exam and/or a simple blood test will rule out pregnancy and other causes of amenorrhea, such as obesity or an underlying medical condition. Treatment depends on the cause, and the localization of the disorder.


U.S. Public Health Service’s Office on Women’s Health. (2000). Menstruation. National Women’s Health Information Center. Retrieved August 15, 2002, from