Delayed puberty and amenorrhea.

The ability to diagnose and manage disorders that cause delayed puberty requires a thorough understanding of the physical and hormonal events of puberty. Wide variation exists within normal pubertal maturation, but most adolescent girls in the United States have begun to mature by the age of 13. Delayed puberty, a rare condition in girls, occurs in only approximately 2.5% of the population. Constitutional delay, genetic defects, or hypothalamic-pituitary disorders are common causes. Amenorrhea, often found as a symptom of delayed puberty, may be due to congenital genital tract anomalies, ovarian failure, or chronic anovulation with estrogen presence or with estrogen absence.