What is human growth hormone?

Human growth hormone (HGH) is a small protein made naturally by the body. It is made in a part of the brain called the pituitary gland. It travels in your blood to all parts of your body to help your body grow.

HGH is very important in growth and development. It controls your growth by telling your liver to make other important hormones for development. Children need HGH to grow normally. It is not as critical in adults, but HGH helps make sure there you have enough muscle and fat in your body to function well. It also keeps your bones healthy.

What is human growth hormone deficiency?

Some people do not make enough HGH. This is known as growth hormone deficiency. A type of growth hormone, designed to be similar to natural HGH, can be used to treat people who do not have enough HGH.

What is excess human growth hormone?

Some people make too much HGH. This is known as excess growth hormone. It can lead to a condition called acromegaly or gigantism.

What are the symptoms of HGH deficiency?

A low level of HGH can cause your child to grow more slowly. They may be smaller in size than other children their age.

In adults, a low level of HGH can cause problems with fitness and health, including:

• brittle and weak bones, possibly leading to osteoporosis
• low muscle mass and strength
• increased fat around the waist
• fatigue and low energy levels

What are the symptoms of excess HGH?

A high level of HGH can cause children to be very tall, sometimes called gigantism. Too much HGH in children can also cause:

• weakness
• delayed puberty
• headaches

In adults, a high level of HGH can cause your bones to grow too much. This is called acromegaly. It can make your hands and feet very large. Sometimes too much HGH can make your face look unusual. This is because the bones in your face have grown too much.

If gigantism or acromegaly are not treated, they can lead to problems such as:

• type 2 diabetes
• cardiovascular disease
• high blood pressure
• arthritis

What causes changes in human growth hormone levels?

Excess HGH is usually caused by a tumour (lump) in the pituitary gland.

HGH deficiency may be caused by:

• a tumour in the pituitary gland or hypothalamus
• damage to the brain — by injury, surgery or radiation treatment
• brain bleed or infection
• genetic abnormalities
• problems with brain development before birth
• Prader-Willi syndrome

HGH levels also decrease as you get older.

How are human growth hormone levels tested?

HGH levels are tested using special blood tests.

HGH deficiency can be diagnosed with a growth hormone stimulation test. This is where you are given a medicine that should make your pituitary gland release HGH. Blood samples are then taken at regular intervals over the next few hours. If your HGH level stays low, you may have HGH deficiency.

Excess HGH can be diagnosed with a growth hormone suppression test. This is where you drink a glucose solution (sugary drink), which should make your HGH levels lower. Blood samples are taken before and after you drink. If your HGH level stays high afterwards, you may have excess HGH.

Other hormone levels might be tested at the same time, to check how well your pituitary gland is functioning.

When should I see my doctor?

If you or your child show symptoms of HGH excess or deficiency, speak to your doctor.

How is growth hormone deficiency treated?

A synthetic (artificial) type of growth hormone can be used to treat children with growth problems. Your doctor can prescribe growth hormone injections, if your child needs them.

Growth hormone can also be given to adults who do not make enough HGH, such as people with Prader-Willi syndrome.

Medicare may cover the cost of growth hormone for people with severe HGH deficiency. You can find more information for children and adults on at Services Australia.

What are the complications of growth hormone treatment?

Using growth hormone that your doctor prescribed for you is generally safe. Your doctor will carefully check your dose so that you don’t experience problems.

After the growth hormone injection, you may have swelling at the site of the injection. Some people experience other side effects such as:

• headaches after the injection
• joint or muscle pain
• high blood pressure
• carpal tunnel syndrome

Some bone problems, like scoliosis, may get worse. This can happen if growth hormone treatment causes your bones to grow too quickly.

Growth hormone treatment can also increase your risk of developing cancer and diabetes. The risk is very small in healthy children.

Unsafe and illegal use of growth hormone

Using growth hormone without a prescription from a doctor can cause serious health problems. Some people use growth hormone to make their muscles grow larger. This is very risky. It can cause:

• acromegaly (too much bone growth)
• diabetes
• high blood pressure
• liver damage
• heart problems
• premature aging (growing older before your time)

Using growth hormone is banned in competitive sports.

Illegal growth hormone may not be what it claims to be. You do not always know what you might be injecting into your body.

Resources and support

If you have questions about growth hormone, or you are concerned about your child's growth, talk to your doctor.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.

For more information, visit:

• the Royal Children's Hospital Melbourne page on growth, pituitary and pubertal disorders.
• the Australian Pituitary Foundation guide to pituitary conditions.
• the Hormones and Me fact sheets about growth problems in children and growth hormone treatment.

Other languages

Fact sheets are available at Hormones Australia in community languages.