Amenorrhea is classified as primary or secondary. It is important to remember that it actually is a symptom and not a diagnosis. Primary amenorrhea refers to absence of menses by the age of 16 years regardless of the presence or absence of normal growth or secondary sexual characteristics. It also has been used to refer to the absence of both menses and normal growth without signs of secondary sexual characteristics by the age of 14 years. Secondary amenorrhea is the cessation of menses for three cycles or more in women who have been menstruating previously and who are not yet considered menopausal.

For the purposes of this book, only secondary amenorrhea is discussed. Any young woman meeting the criteria for primary amenorrhea should be scheduled for a proper reproductive endocrinology evaluation. You should be familiar with your practice’s scheduling preference for young women reporting primary amenorrhea.

Amenorrhea is a common problem particularly as a woman begins menstruation and as she nears menopause. It also may be a common side effect of certain hormonal medications. Women on certain medications, including some contraceptives and hormone replacement therapies, may have lack of menstruation as a side effect. Low body fat, thyroid problems, stress, and pituitary problems may result in amenorrhea, too.