Normal Growth And Development Of Adolescents

Who are adolescents?

Adolescents are children who are 10 to 20 years of age. They are in a period between childhood and adulthood, called adolescence. This time period is divided into three stages, including early (10 to 13 years of age), middle (14 to 17 years of age), and late (18 to 20 years of age). During this time, your child will go through many changes in his physical, psychological (mental and emotional), and social growth.

What physical changes occur during adolescence?

Your child's body changes quickly during puberty. Puberty is a period in adolescence where the body develops and matures sexually. This period usually starts at 7 to 13 years of age in girls, and 9 to 14 years of age in boys. Hormones (special chemicals in the body), family history, and nutrition all add to your child's growth.

  • Body make-up:

    • Boys: Bones and muscles grow, and strength increases. Fat is lost in some parts of the body, such as the arms and legs. Broad shoulders may develop. Body odor becomes adult-like and acne (pimples) may appear. Their voice deepens and hair begins to grow on the face, pubic area, underarms, and other parts of the body.

    • Girls: Girls store more fats than boys. Their body develops with wider hips and smaller waistlines. Their body odor and voice change. Pubic and underarm hair starts to appear and grow. They may also get acne.

  • Sexual growth:

    • Boys: Hair over the pubic area increases in amount, and becomes darker, thicker, and curlier. At 11 to 12 years of age, the penis and testes begin to enlarge while the scrotum begins to thin out and redden. At about 13 years of age, boys may start making sperm and may ejaculate or have wet dreams.

    • Girls: Breasts begin to develop. This usually occurs at 8 to 13 years of age. Around two years later, they usually start menstruating (having a monthly period). Menstrual cycles may be irregular for the first few years. This means that girls may miss monthly periods once in a while. Irregular periods may last for as long as seven years after they begin.

  • Height:

    • Boys: Boys grow about 4 inches per year during this time frame. During early adolescence, their height may reach 55 to 63 inches. Later, they grow to a height of 65 to 69 inches. Their full height reaches about 69 to 70 inches. On average, boys grow about 11 inches in their height during this time frame.

    • Girls: Girls are usually two years ahead of boys in height. They increase in height the fastest at age 12, growing 3 and one-half inches per year. During early adolescence, they usually grow to a height of 55 to 63 inches. Girls reach about 64 and one-half inches for their full height. Girls grow about 10 inches during this time frame.

  • Weight:

    • Boys: Boys increase their weight fastest when their height growth is also fastest. This occurs at around 14 years of age. Boys in early adolescence weigh around 73 to 114 pounds. Later, most boys weigh about 121 to 149 pounds, and this increases to 159 to 161 pounds. Increase in weight is around 20 pounds per year. Weight gained during this time frame is about 50 percent of an adult's body weight.

    • Girls: Weight starts to increase fastest about six months after a girl reaches her full height. Girls weigh about 75 to 114 pounds during early adolescence, increasing to 118 to 132 pounds, and ending at 130 to 134 pounds. Girls gain about 18 pounds per year after about 12 and one-half years of age.

What mental changes occur during adolescence?

As a child matures, he learns to think more deeply.

  • Change in self-image: Young adolescents often focus on their own self-image. Through different experiences, your child may find new beliefs and question old ones. He begins to form personality traits that define who he is. He defines his own ideals, values, and principles. By late adolescence, he is happier with who he is, and his place in society.

  • Intellectual development and skills: Adolescents learn to think in new ways to understand complex ideas. They learn through selective and divided attention, and better memory. Problem solving skills also improve. They are able to think in a logical way, use sound judgment, and develop abstract thinking. Abstract thinking is the ability to understand and make sense out of symbols or images.

  • Setting goals and ambitions: As an adolescent learns who he is, he begins to plan for the future. Based on his beliefs and values, he decides who he wants to be and what he wants to do in life. He sets realistic goals and has learned the difference between goals, fantasy, and reality. By late adolescence, he begins to work hard to reach his goals.

What social changes occur during adolescence?

  • Family: An adolescent may begin to spend less time with parents and more with friends. He often longs for freedom and starts to detach himself from his family. He begins to depend on himself more and learn responsibility.

  • Friends: During early adolescence, having close relationships and being accepted into a peer group is very important. A child's actions can be greatly changed by peers or peer pressure. More time spent with friends gives a child more chances to try new things. He may try smoking, drinking alcohol, or sexual activity. By middle adolescence, boys and girls start to become friends, which often leads to dating.

  • Community: As a child grows older, his relationships with others also grow. By late adolescence, he learns to think about the needs of others instead of thinking only of himself.

What problems may occur during adolescence?

  • Early or delayed puberty: The age a child enters puberty depends on many things. Some children develop sexually sooner or later than others. Girls go through puberty earlier than boys. Precocious (early) puberty is when a girl younger than 8 years of age starts to develop sexually. In boys, early puberty may start younger than nine years of age. Delayed puberty is when a girl over 13 years of age or a boy over 14 or 15 years of age has not shown signs of puberty. Early or delayed puberty may be caused by certain medical conditions.

  • Low self-esteem: Your child may not feel good about himself, especially during early adolescence. Most children focus on their bodies as changes occur, and this may cause poor body image. Your child may worry about how he is growing, and things like acne may be a concern. It is normal for your child to not be happy with how he looks, and to compare himself with his peers.

  • Mood problems or depression: Mood problems such as depression or anxiety may affect adolescents. These often occur because of changes during puberty. Deep depression is serious and may lead to thoughts or attempts of suicide.

  • Need for independence: Adolescents seek freedom. They tend to move away from their parents emotionally, and feel comfortable with their peers. This may lead to conflict and problems between you and your child. He may begin to reject your rules and values, and struggle to learn who he is. These problems tend to resolve by late adolescence. As a child grows, he becomes more stable emotionally, learns to rely on himself, and shows more concern for others.

  • Poor nutrition or low physical activity: Unhealthy eating habits and lack of physical activity can lead to children being underweight, overweight, or at risk of growing overweight. These conditions may lead to medical problems, such as diabetes (high blood sugar), hypertension (high blood pressure), and hyperlipidemia (high blood cholesterol).

  • Risky behaviors: As your child starts making his own choices, peer pressure may cause poor judgment. He may choose to take unsafe risks. Risky behaviors include trying drugs, alcohol, cigars or tobacco. They also include getting into physical fights or having risky sex. They may decide not to wear seatbelts or helmets, drive while drunk, or carry a weapon. A child is more likely to do these things if he has problems with self-control, family, or the community. Younger adolescents that cannot control their temper often act without thinking about the results of their actions. Children often practice the same bad habits of their parents, such as using drugs or drinking too much alcohol. The school, work, peers, and media (radio and TV) may also direct a child's actions.

How can I help keep my adolescent safe?

  • Have your adolescent seen by caregivers: Children who are sexually active, smoke tobacco, use street drugs, or binge drink may benefit from talk therapy, or counseling. Binge drinking is having more than five drinks during one time period.

  • Know your child: Get involved in your child's activities. Spend time with him, and be there when he needs you. Stay in contact with your child's teachers to find and deal with problems early. Get to know his friends. If he has a job, make sure that it does not get in the way of school.

  • Promote good nutrition and physical activity: Make sure your child eats a balanced diet and limits the amount of foods high in fat and sugar. Eating fruits and vegetables are good for him. Encourage him to exercise regularly, at least 30 minutes every day. Ask caregivers if your child needs to use a vitamin and mineral supplement.

  • Set clear rules that do not change: Be a good role model for your child. Limit television and movies. Even if your child is older, limit the amount of violence, sex, and drugs and alcohol use that he sees. Talk about the dangers of sex, alcohol, and drug use. TV and movies make these things seem OK and often do not show the results of making poor choices.

  • Talk to your child: Talk to your adolescent about the risks of being sexually active. Teach him about birth control and protection against sexually transmitted diseases.

  • Teach road safety: Explain to your child why he must wear helmets or seat belts. Help him understand the risk of riding with a driver who has used drugs or drank alcohol.

  • Understand your child's actions and signs: Learn the signs of drug use, early sexual activity, depression, and eating problems, such as anorexia nervosa (starving to stay thin). Knowing the early signs of problems can give you a chance to get your child help before problems get more serious.

Where can I find more information?

  • American Academy of Pediatrics
    141 Northwest Point Boulevard
    Elk Grove Village , IL 60007-1098
    Phone: 1- 847 - 434-4000
    Web Address:
  • American Academy of Family Physicians
    11400 Tomahawk Creek Parkway
    Leawood , KS 66211-2680
    Phone: 1- 913 - 906-6000
    Phone: 1- 800 - 274-2237
    Web Address:

Care Agreement

You have the right to help plan your child's care. To help with this plan, you must learn about your child's growth and development. You can then discuss treatment options with his caregivers. Work with them to decide what care will be used to treat your child.The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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