Puberty

Jeff hates gym class. It's not that he minds playing soccer or basketball or any of the other activities. But he does dread going into the locker room at the end of class and showering in front of his friends. Although the other guys' bodies are growing and changing, his body seems to be stuck at a younger age. He's shorter than most of the other guys in his grade, and his voice hasn't deepened at all. It's embarrassing to still look like a little kid.
Abby knows what it's like to feel different, too. The bikini tops that her friends fill out lie flat on her. Most of them have their periods, too, and she hasn't had even a sign of one. Abby doesn't even really have to shave her legs or underarms, although she does it just to be like everyone else.
Both Jeff and Abby wonder and worry, "What's wrong with me?"
What Is Delayed Puberty? Puberty is the time when your body grows from a child's to an adult's. You'll know that you are going through puberty by the way that your body changes. If you're a girl, you'll notice that your breasts develop and your pubic hair grows, that you have a growth spurt, and that you get your period (menstruation). The overall shape of your body will probably change, too - your hips will widen and your body will become curvier.
If you're a guy, you'll start growing pubic and facial hair, have a growth spurt, and your testicles and penis will get larger. Your body shape will also begin to change - your shoulders will widen and your body will become more muscular.
These changes are caused by the sex hormones (testosterone in guys and estrogen in girls) that your body begins producing in much larger amounts than before.
Puberty takes place over a number of years, and the age at which it starts and ends varies widely. It generally begins somewhere between the ages of 7 and 13 for girls, and somewhere between the ages of 9 and 15 for guys, although it can be earlier or later for some people. This wide range in age is normal, and it's why you may develop several years earlier (or later) than most of your friends.
Sometimes, though, people pass this normal age range for puberty without showing any signs of body changes. This is called delayed puberty.
What Causes Delayed Puberty?There are several reasons why puberty may be delayed. Most often, it's simply a pattern of growth and development in a family. A guy or girl may find that his or her parent, uncle, aunt, brothers, sisters, or cousins developed later than usual, too. This is called constitutional delay (or being a late bloomer), and it usually doesn't require any kind of treatment. These teens will eventually develop normally, just later than most of their peers.
Medical problems also can cause delays in puberty. Some people with chronic illnesses like diabetes, cystic fibrosis, kidney disease, or even asthma may go through puberty at an older age because their illnesses can make it harder for their bodies to grow and develop. Proper treatment and better control of many of these conditions can help make delayed puberty less likely to occur.
A person who's malnourished - without enough food to eat or without the proper nutrients - may also develop later than peers who eat a healthy, balanced diet. For example, teens with the eating disorder anorexia nervosa often lose so much weight that their bodies can't develop properly. Girls who are extremely active in sports may be late developers because their level of exercise keeps them so lean. Girls' bodies require a certain amount of fat before they can go through puberty or get their periods.
Delayed puberty can also happen because of problems in the pituitary or thyroid glands. These glands produce hormones important for body growth and development.
Some people who don't go through puberty at the normal time have problems with their chromosomes (pronounced: kro-muh-soamz), which are made up of DNA that contain our body's construction plans. Problems with the chromosomes can interfere with normal growth processes.