Teens going through puberty will have many changes in their developing bodies as growth surges and muscles change shape.

There's a very broad range of time in which kids hit puberty-related growth spurts:

• Most girls start their sexual development between the ages of 8 and 13 (the average age is 12), and have a growth spurt between the ages of 10 and 14.
• Most boys start developing sexually between the ages of 10 and 13, and continue to grow until they're around 16.

Growth and Changes During Puberty

Puberty — or sexual development — is a time of dramatic change for both boys and girls. Hormone-driven changes are accompanied by growth spurts that transform kids into physically mature teens as their bodies develop.

It's important for them to have healthy eating habits, a well-balanced diet, and some physical activity each day to ensure continued growth and proper development during these years.

Changes in Girls

Events in girls as they go through puberty:

• Breasts begin to develop and hips become rounded.
• An increased rate of growth in height begins.
• Pubic hair begins to appear, usually within 6 to 12 months after the start of breast development.
• The uterus and vagina, as well as labia and clitoris, increase in size.
• Pubic hair is well established and breasts grow further.
• The rate of growth in height reaches its peak about 2 years after the start of puberty.
• Menstruation begins, almost always after the peak growth rate in height (average age is 12.5 years).

Once girls start to menstruate, they usually grow about 1 or 2 more inches, reaching their final adult height by about age 14 or 15 years (younger or older depending on when puberty began).

Changes in Boys

Boys tend to show the first physical changes of puberty between the ages of 10 and 16. They tend to grow most quickly between ages 12 and 15. The growth spurt of boys is, on average, about 2 years later than that of girls. By age 16, most boys have stopped growing, but their muscles will continue to develop.

Other features of puberty in boys include:

• The penis and testicles increase in size.
• Pubic hair appears, followed by underarm and facial hair.
• The voice deepens and may sometimes crack or break.
• The Adam's apple, or larynx cartilage, gets bigger.
• Testicles begin to produce sperm.

At the Doctor's Office

Normal growth — supported by good nutrition, enough sleep, and regular exercise — is one of the best overall indicators of your teen's good health.

Despite data collected for growth charts, "normal" heights and weights are difficult to define. Your teen's growth pattern is largely determined by genetics. Shorter parents, for instance, tend to have shorter kids, whereas taller parents tend to have taller kids.

Although you may worry if your child isn't as tall as other classmates, the more important question is whether your child is continuing to grow at a normal rate. If your doctor detects a problem — such as a growth rate that had been normal but has recently flattened — he or she may track your child's measurements carefully over several months to see whether the growth pattern suggests a possible health problem or is just a variation of normal.

It's not unusual for teens to have their own concerns about how they're growing and how they look. Girls can be very critical of their own weight, which can sometimes lead to unhealthy body image concerns and dieting practices. Boys tend to be more concerned with their height and muscle development, which can also lead to unhealthy practices, like using steroids and protein supplements.

If you're concerned about your teen's body image, or eating and exercise habits, talk with the doctor.

Many teens worry a lot about being different from their peers and about anything that would make them not fit in or seem "normal." Encourage your teen to bring up any of these concerns with the doctor, if he or she feels comfortable doing so. The doctor can provide reassurance that other kids have the same concerns about their size.

If you have any other concerns about your teen's growth or development, talk with your doctor.