Evaluation and management of adolescent amenorrhea.

During the first years of menstruation it is not rare for a girl to present with an irregular menstrual pattern. The complete absence or cessation of menses, which is defined as amenorrhea, requires careful evaluation and management. It is divided into primary and secondary types that describe the occurrence of amenorrhea before and after menarche, respectively. The list of causes is long and includes anatomical or functional anomalies of the genital tract, hormonal disorders, and multifactorial reasons. The most common causes are hypothalamic amenorrhea, polycystic ovarian syndrome, hyperprolactinemia, and ovarian failure. A thorough medical history and careful clinical examination of the young girl is absolutely essential. The distinction between primary and secondary amenorrhea, together with the presence, or not, of secondary sexual characteristic development will guide the physician to the differential diagnosis of amenorrhea. Essential laboratory examinations include follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), and prolactin measurements; while in the presence of acne or hirsutism, androgen levels should also be measured. Management should focus on the restoration of ovulatory cycles and the prevention of short- and long-term consequences of hormonal imbalance.