People grow to an average height thanks to growth hormones that are produced by special glands in the brain. People who are taller or shorter than average may have an excess or deficiency of growth hormone.
Hormones Defined
Hormones are chemicals that are supposed to be in your body to control various functions such as growth, energy, reproduction, and mood. Hormones are produced by special glands based on chemical instructions sent out by the master gland which is called the pituitary gland. The pituitary gland, which is located at the base of the brain, also produces growth hormone, which is abbreviated GH.
Growth hormone, as the name suggests, is the hormone that controls your body’s growth. GH is very important in childhood development as it helps children grow taller byl regulating the growth of bones and cartilage. It also helps increase muscle mass and decrease body fat as children grow. GH continues to work after we reach our adult height by controlling the body’s metabolism including how the cells of the body use food for energy.
Growth Hormone Deficiency
Children who have a growth hormone deficiency do not produce enough growth hormone. They may be smaller than normal at birth, or may start growing at a normal rate, but slow down after they reach 2 to 3 years. Because the length of skeletal bones is complete by the end of puberty, children with GH deficiency who are not treated before puberty may never reach a normal adult height. They may be as short as 3-4 feet tall, but they are generally proportioned normally with arms and legs that look the right length for their bodies. This condition is known as pituitary dwarfism.
Excess Growth Hormone
It is also possible to have higher than normal levels of GH. Children with excess GH tend to become very tall, and may grow to be over 7 feet as adults. Their arms and legs may also look longer than normal for the rest of their bodies. Excess GH can be caused by a non-cancerous tumor in the pituitary gland. If this develops in an adult, the bones in the hands, feet, and head may become thicker than normal, causing them to look large for the rest of the body. This condition is known as acromegaly.
An estimated 10,000 to 15,000 children in America have GH deficiency, while an excess of GH is very rare.
Further reading:
Children with Growth Hormone Deficiency Can Grow to a Normal Size
Sources:
The Hormone Foundation
National Institutes of Health: Medline Plus
The Columbia Encyclopedia
Children’s Hospital Boston