Puberty is the time when the physical signs of sexual maturity (secondary sexual characteristics) appear due to the secretion of sex hormones in older children. Puberty is earlier in girls (8 to 13 years) than boys (10 to 15 years). The timing of puberty has become progressively earlier over the past 100 years. A marked growth spurt occurs during puberty. There are also many emotional and social changes.

Puberty may occur too early (precocious puberty) or too late (delayed puberty). Both may be due to endocrine disorders. Therefore, these children must be referred for a specialist opinion. Precocious puberty is more common in girls.