Do you feel like the smallest person in your class? Guys and girls who are shorter may feel out of sync with their peers — just as guys who mature earlier may feel strange if they shave first or girls who get their periods before their friends may feel awkward. In most cases, teens who are small are probably just physically maturing a little bit more slowly than their friends. Or maybe their parents are smaller and they take after them.
Occasionally, though, there's a medical reason why some people grow more slowly than usual.
What's Normal and What's Not
Kids and teens grow and go through puberty at different times. For girls, puberty usually begins between ages 8 and 13. For guys it often begins a bit later — between 10 and 15.
Girls become more rounded in the hips and their breasts begin to develop. Usually, about 2 years after their breasts begin to develop, girls begin to menstruate, or get their periods. Guys' penises and testicles grow larger and both guys and girls grow hair in their pubic areas and under their arms. Guys get more muscular, begin to grow hair on their faces, and their voices get deeper.
Some teens develop a lot earlier than their friends (called precocious puberty), whereas others develop much later than other people of the same age (called delayed puberty).
Kids and teens may not grow as fast as their peers for many reasons. If you're short, you may just have familial (genetic) short stature. In other words, short parents tend to have short children. If a doctor finds you have no growth disorder and you're growing steadily and sexually maturing at the usual expected age, then you can probably expect to grow to a normal size, although you may be somewhat shorter than average.
Some teens have constitutional growth delay. These teens grow at a normal rate when they are younger kids, but they lag behind and don't start their pubertal development and their growth spurt until after most of their peers. People who have constitutional growth delay are often referred to as "late bloomers." If a kid or teen appears to have constitutional growth delay, a doctor might take X-rays of bones and compare them with X-rays of what's considered average for that age. Teens with constitutional growth delay tend to have bones that look younger than what's expected for their age. These teens will have a late growth spurt and continue growing and developing until an older age. They usually catch up with their peers by the time they are young adults.
Not getting adequate amounts of protein, calories, and other nutrients in your diet can also cause growth to slow, as well as a number of other chronic medical conditions such as kidney, heart, lung, and intestinal diseases. People with sickle cell anemia may also grow and develop more slowly. Following the treatment plan worked out with a doctor can help teens with health conditions achieve a more normal growth pattern.
What Are Growth Disorders?
There are other reasons why teens may have growth problems, though. Growth is controlled by the hormones the body produces. Many diseases of the endocrine system, which is made up of the glands that produce hormones, can affect growth.
Hormones are secreted by the endocrine glands and carried throughout the body in the bloodstream. The hypothalamus (part of the brain) controls the pituitary gland, which in turn releases some of the hormones that control growth and sexual development. Estrogen and testosterone are important hormones that drive sexual development and function and also play a role in growth.
Hypothyroidism can cause slow growth because the thyroid gland isn't producing enough thyroid hormone, which is necessary to support normal growth. A major symptom of hypothyroidism is feeling tired or sluggish. A blood test measuring thyroid levels can show if someone has this disorder, which can develop at any time in life and is common in teen girls and women of childbearing age.
Some diseases aren't caused by the hormones, but they can impact the body's ability to produce the hormones needed to grow and develop. For example, Turner syndrome is a genetic condition (due to a problem with a person's genes) that occurs in girls. It is caused by a missing or abnormal X chromosome. Girls with Turner syndrome tend to be short and don't usually undergo normal sexual development because their ovaries (organs in the lower abdomen that produce eggs and female hormones) don't mature and function normally.
Another condition that can lead to significantly short stature is dwarfism. Dwarfism results from abnormal growth of the bones and cartilage in the body. In many forms of dwarfism the person has abnormal body proportions, such as noticeably short limbs. Most cases of dwarfism are genetic.
Growth Hormone Deficiency
One growth disorder that is specific to the hormones that govern growth is called growth hormone deficiency (GH deficiency). This condition involves the pituitary gland, the small gland located at the base of the brain that produces growth hormone and other hormones. If the pituitary gland doesn't produce enough hormones for normal growth, growth slows down or stops.
GH deficiency can occur at any age, and the most common sign in kids and teens is a slowing of growth to less than 2 inches (5 centimeters) a year. Kids with this disorder usually have normal body proportions — in other words, their bodies look normal, just smaller. Growth hormone deficiency does not affect intelligence or brain function.
The cause of growth hormone deficiency can be an underdeveloped, damaged, or malfunctioning pituitary gland or hypothalamus, which can happen before or during birth or can be caused later by an accident or trauma or certain diseases. Tumors near the pituitary gland, like craniopharyngioma (pronounced: kray-nee-o-far-un-jee-o-muh), can also damage the hypothalamus and pituitary gland and affect growth. In most cases, though, the cause of growth hormone deficiency is simply unexplained.
Growth hormone deficiency usually affects only one person in a family and isn't generally passed on from parents to children.
What Do Doctors Do?
Your doctor has probably been charting your growth since you were born to make sure there is a "growth curve" showing steady growth in weight and height. If this curve flattens out, a doctor usually does a thorough physical exam and may order special blood tests and X-rays of the bones.
Your doctor will also look at growth patterns in your family. Teens with familial short stature have inherited this trait from their parents. And teens with constitutional growth delay often have close relatives who were also late bloomers.
Growth conditions like familial short stature or constitutional growth delay usually don't require any special treatment. Extra vitamins or special diets won't make a person with one of these conditions grow any taller or faster. Occasionally, though, doctors will give hormone treatment — usually testosterone — to guys with constitutional growth delay who are having a rough time waiting for puberty to kick in. The treatments can temporarily increase growth and development until the guy starts producing puberty hormones on his own.
If a doctor finds that someone has growth hormone deficiency, it can be treated by replacing the missing hormone. The replacement hormone is produced in a laboratory and is given as a daily shot. Taking the hormone by mouth doesn't work because the hormone is destroyed by the stomach's digestive juices. Depending on when the diagnosis is made, treatment usually lasts for several years — until the growth areas of the bones close (after that, no more growth can occur).
It can take weeks or months to notice the effects of growth hormone replacement, but most kids will grow two to five times faster during the first year of treatment than they were growing beforehand. The rate of growth after that is usually somewhat slower, about 3 to 4 inches (7.6 to 10.2 centimeters) per year.
Recently, growth hormone treatment has been approved for some kids and teens who are not growth hormone deficient but who appear to be headed for a very short adult height (under 5 feet, 4 inches [1.6 meters] for boys and under 4 feet, 11 inches [1.5 meters] for girls). This treatment can help increase somebody's final height by about 2 to 3 inches (5 to 7.6 centimeters).
Growth disorders that are caused by other conditions also can be treated. Girls with Turner syndrome can benefit from growth hormone and estrogen therapy. Thyroid medication can be help restore a normal growth rate in kids and teens with hypothyroidism. In most cases, growth will also improve with specific treatment of chronic medical conditions that are slowing a teen's growth.
Dealing With Growth Disorders
It can be tough having a growth disorder as a teen because it can affect a person's body image and self-esteem. Talking with a mental health professional is one way some teens deal with feelings and concerns about their growth.
Your doctor can also be a good resource for advice on your growth pattern. And, although no one has much control over the changes taking place in their bodies during puberty, you can do what you can to keep your body in top shape by eating a healthy diet, getting enough sleep, and exercising.
Reviewed by: Steven Dowshen, MD
Date reviewed: April 2007
