children s health issues
Physical Growth and Sexual Maturation of Adolescents
Sexual Maturation in Adolescents
Sexual maturation or puberty begins at different ages depending on genetic and environmental factors. Sexual maturity begins earlier today than a century ago, probably because of improvements in nutrition, general health, and living conditions. For example, the average age that girls begin menstruating has decreased by about 3 years over the past 100 years. However, whenever sexual maturation begins, it typically occurs in the same order. sexual changes begin with enlargement of the scrotum and testes, typically followed by lengthening of the penis (see Puberty in Boys ). Next, pubic hair appears. Armpit and facial hair appears about 2 years after pubic hair. The growth spurt usually begins a year after the testes start enlarging. Boys in the United States typically have their first ejaculation between 12½ years and 14 years of age, about 1 year after penis growth accelerates. Young adolescent boys often have slight enlargement of the breasts ( breast budding is the first sign of sexual maturation, followed closely by the start of the growth spurt (see Puberty in Girls ). Shortly after that, pubic and armpit hair appears. Menstruation typically begins about 2 years after breast development starts and when growth in height slows after reaching its peak velocity. In the United States, most girls start their period at 12 or 13 years of age, but there is a wide range. In both boys and girls, pubic and/or axillary hair may appear first. This appearance may be a normal variation but should be discussed with a doctor. If sexual maturation begins too early (see Early Puberty ) or is very delayed (see 