Pathophysiology
Clinical meaning
Precocious puberty occurs when secondary sexual characteristics develop before age 8 in girls or before age 9 in boys. The hypothalamic-pituitary-gonadal axis activates prematurely, causing early production of sex hormones. This leads to early breast development, pubic hair growth, and menarche in girls, or testicular enlargement and pubic hair in boys. Early exposure to sex hormones accelerates bone maturation, which initially causes a growth spurt but leads to early epiphyseal closure and ultimately shorter adult height. The condition may be central (brain-mediated) or peripheral (from ovarian, testicular, or adrenal sources).