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
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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