Secondary Amenorrhea
The term for absent menses in a woman who has previously menstruated and is not pregnant, breastfeeding, or menopausal is "secondary amenorrhea." 1, 2, 3
Definition and Diagnostic Timeframes
Secondary amenorrhea is formally defined as the cessation of previously established menstruation for longer than 6 months. 1, 2 However, there is an important nuance in the diagnostic criteria:
- For women with previously regular cycles, amenorrhea can be diagnosed after just 3 months of absent menses 3, 4, 5
- For women with previously irregular cycles, the full 6-month absence is required for diagnosis 3, 6
This distinction matters clinically because it allows earlier intervention in women whose baseline pattern was regular, where a 3-month absence represents a more significant deviation from their norm. 3
Epidemiologic Context
- Secondary amenorrhea affects approximately 3-4% of women in the general population 1, 2
- This makes it a relatively common presenting complaint in primary care and gynecology settings 1
Clinical Caveat: When Earlier Evaluation is Warranted
While the formal definitions use 3-6 month timeframes, evaluation should begin immediately if red flag symptoms are present, regardless of duration: 3
- Galactorrhea (suggesting hyperprolactinemia) 7, 3
- Headaches or visual changes (suggesting pituitary pathology) 1, 3
- Signs of eating disorder or significant weight loss 1, 3
- Symptoms of hyperandrogenism or thyroid dysfunction 3
Special Population: Contraceptive Users
Amenorrhea occurring in the context of hormonal contraceptive use does not require medical treatment and is generally not harmful, even when prolonged beyond 6 months. 3 This represents an important exception where the absence of menses is iatrogenic and expected, not pathologic.