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 probably are just physically maturing a little slower than their friends. Or maybe their parents are short and they take after them.

Occasionally, though, there's a medical reason why some people grow more slowly than usual.

What's Normal Growth Like?

Kids and teens grow and go through puberty at different times. For girls, puberty usually begins between ages 7 and 13. For guys it often begins a bit later — between 9 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 guys and girls both 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. During puberty, both guys and girls go through growth spurts.

What Can Slow Growth?

Some teens develop a lot earlier than their friends (called precocious puberty). Others can develop much later than other people of the same age. This is 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're growing steadily and sexually maturing at the right age, then you can probably expect to grow to a normal size, although you may be somewhat shorter than average.

Teens who have constitutional growth delay grow at a normal rate when they're younger, 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 might have constitutional growth delay, a doctor might take X-rays of the wrist and compare them with X-rays of what's considered average for that age. Teens with constitutional growth delay 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're young adults.

Teens might have slower growth if they:

• don’t get enough protein, calories, and other nutrients in their diet
• have a long-lasting (chronic) medical condition, such as problems with the kidneys, heart, lungs, and intestines
• have sickle cell anemia

Following the treatment plan worked out with a doctor can help teens with health problems grow better. 

What Are Growth Disorders?

Teens may have growth problems for other reasons. Growth is controlled by the hormones the body makes. Many diseases of the endocrine system can affect growth.

Endocrine glands release hormones that travel 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 making enough thyroid hormone, which is needed to support normal growth. A blood test can show if someone has low thyroid hormone levels. Some causes of poor growth are genetic (a problem with a person’s genes). For example, Turner syndrome is a genetic condition that happens in girls. It is caused by a missing or abnormal X chromosome. Girls with Turner syndrome tend to be short and don't go through normal sexual development because their ovaries (which make eggs and female hormones) don't mature, so can’t work as they should.

Another condition that can lead to significantly short stature is dwarfism. When a person has dwarfism, bones and cartilage don’t grow normally. In many types of dwarfism, the arms and legs are short and look out of proportion to the rest of the body.

What Is Growth Hormone Deficiency?

Growth hormone deficiency (GH deficiency) is a growth disorder related to the hormones that control growth. This condition involves the pituitary gland, the small gland at the base of the brain that makes growth hormone along with other hormones. If the pituitary gland doesn't make enough hormones, normal growth slows down or stops. Kids and teens with GH deficiency grow less than 2 inches (5 centimeters) a year.

GH deficiency happens if the pituitary gland or hypothalamus is damaged or doesn’t work as it should. A person can be born with it, or it can happen later due to a head injury, brain infection, or brain surgery. Tumors near the pituitary gland, like craniopharyngioma (pronounced: kray-nee-o-far-un-jee-OH-muh), can also damage the hypothalamus and pituitary gland and slow growth.

Most of the time, the cause of growth hormone deficiency is not known.

What Do Doctors Do?

Your doctor has followed your growth since you were a baby. If you stop growing as expected, the doctor will do an exam and may order special blood tests and X-rays of the bones of your wrist.

Your doctor will also look at growth patterns in your family. Teens with familial short will have short 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 need any special treatment. Extra vitamins or special diets won't make a person with one of these conditions grow any taller or faster.