Amenorrhea: A Systematic Approach to Diagnosis and Management.

Menstrual patterns can be an indicator of overall health and self-perception of well-being. Primary amenorrhea, defined as the lifelong absence of menses, requires evaluation if menarche has not occurred by 15 years of age or three years post-thelarche. Secondary amenorrhea is characterized by cessation of previously regular menses for three months or previously irregular menses for six months and warrants evaluation.