<unk>  is when a person lacks or has incomplete development of specific sexual characteristics past the usual age of onset of puberty. The person may have no physical or hormonal signs that puberty has begun. In the United States, girls are considered to have<unk>  if they lack breast development by age 13 or have not started menstruating by age 15. Boys are considered to have<unk>  if they lack enlargement of the testicles by age 14.<unk>  affects about 2% of adolescents. Most commonly, puberty may be<unk>  for several years and still occur normally, in which case it is considered constitutional delay of growth and puberty, a common variation of healthy physical development. Delay of puberty may also occur due to various causes such as malnutrition, various systemic diseases, or defects of the reproductive system (hypogonadism) or the body's responsiveness to sex hormones. Initial workup for<unk>  not due to a chronic condition involves measuring serum FSH, LH, testosterone/estradiol, as well as bone age radiography. If it becomes clear that there is a permanent defect of the reproductive system, treatment usually involves replacement of the appropriate hormones (testosterone/dihydrotestosterone for boys, estradiol and progesterone for girls).
Delayed puberty
Precocious puberty
Late-onset hypogonadism
Prognathism
Oncofertility
Hypogonadotropic hypogonadism
Hyperandrogenism
Male infertility