Physical Development, Ages 15 to 18 Years - Topic Overview
By age 15, most girls have had their first menstrual period
and have completed the rapid
growth spurt that usually occurs during puberty. After
the first period, teenage girls grow
1.5 in. (3.8 cm) to
3 in. (7.6 cm) on average.
Other early changes of puberty, such as the growth of pubic hair and breasts,
have also occurred. Teenage girls tend to complete breast development an
average of 4 years after breast buds signal the beginning of puberty.
The growth spurt in boys tends to reach its peak sometime during the
early to mid-teen years. Although boys lag behind girls in height in early
adolescence, they generally end up being taller than girls by age 18. After
growth starts, boys grow at a faster rate and for a longer period of time.
Also, boys usually continue growth of facial hair, penis and testicles, and
pubic hair during the late teen years.
These and other physical
changes are highly variable by individual. Some individuals are "early
bloomers," and others grow and develop later.