Menstrual problems in adolescents.

Menarche is a significant event in the course of puberty. Although the age of menarche varies among adolescents, it occurs in most adolescents at an SMR of 4. With the onset of ovulatory cycles, local prostaglandins are released, often causing dysmenorrhea. This usually responds to PSIs. Abnormal uterine bleeding usually is the result of anovulatory cycles. However, complications of pregnancy, systemic illnesses, and local pathology must be considered. Significant bleeding usually responds to hormonal therapy. Amenorrhea may result from abnormalities affecting the hypothalamus, pituitary, or ovaries. The evaluation should be done in a logical, orderly fashion. In addition, pregnancy must always be considered first in the differential diagnosis.