Puberty refers to the changes that happen biologically and psychologically as humans transition from childhood toward adulthood.  It involves alterations in hormone levels that affect how bodies grow, including the development of secondary sexual characteristics like breast development in girls (and often temporary breast changes for boys), growth of underarm and pubic hair, and changes in genitals, body fat, and muscle distribution for both sexes. Puberty also means changes in brain development, including some moodiness and possibly impulsivity, but also increasing maturity of thinking and reasoning, leading eventually improved decision-making and self-regulation.  These changes are required for achievement of adult body types, reproductive capability, and adult psychological functioning. Puberty can’t be stopped, but understanding what to expect helps parents and their children manage this potentially difficult time more successfully.