Menstrual disorders in adolescence are common. Although girls may begin menstruating as early as 8 years old or as late as 16, 12 is the average age for the onset of menstruation. While having a period every 28 days has become the “textbook” explanation of normal, cycles vary. In fact, it is especially common for teen girls to have irregular cycles.

Amenorrhea
Amenorrhea, or the absence of a menstrual period (usually characterized by a missing period for more than three months), is a common disorder in adolescence. Primary amenorrhea describes the condition of no menstruation at puberty. This is usually a lifelong condition. Secondary amenorrhea, the more common form, describes once “normal” periods that have become abnormal, irregular or absent.

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