Alternative names for growth hormone
Somatotropin; GH; human growth hormone; HGH
What is growth hormone?
Growth hormone is released into the bloodstream from the anterior pituitary gland. The pituitary gland also produces other hormones that have different functions from growth hormone.
Growth hormone acts on many parts of the body to promote growth in children. Once the growth plates in the bones (epiphyses) have fused growth hormone does not increase height. In adults, it does not cause growth but it helps to maintain normal body structure and metabolism, including helping to keep blood glucose levels within set levels.
How is growth hormone controlled?
Growth hormone release is not continuous; it is released in a number of ‘bursts’ or pulses every three to five hours. This release is controlled by two other hormones that are released from the hypothalamus (a part of the brain): growth hormone-releasing hormone, which stimulates the pituitary to release growth hormone, and somatostatin, which inhibits that release.
Growth hormone levels are increased by sleep, stress, exercise and low glucose levels in the blood. They also increase around the time of puberty. Growth hormone release is lowered in pregnancy and if the brain senses high levels of growth hormone or insulin-like growth factors already in the blood.
What happens if I have too much growth hormone?
Not surprisingly, too much growth hormone causes too much growth. In adults, excessive growth hormone for a long period of time produces a condition known as acromegaly, in which patients have swelling of the hands and feet and altered facial features. These patients also have organ enlargement and serious functional disorders such as high blood pressure, diabetes and heart disease. Over 99% of cases are due to benign tumours of the pituitary gland, which produce growth hormone. This condition is more common after middle-age when growth is complete so affected individuals do not get any taller.
Very rarely, increased growth hormone levels can occur in children before they reach their final height, which can lead to excessive growth of long bones, resulting in the child being abnormally tall. This is commonly known as gigantism (a very large increase in height).
Overproduction of growth hormone is diagnosed by giving a sugary drink and measuring the growth hormone level over the next few hours. The sugar should cause growth hormone production to reduce. However, this does not happen in acromegaly.
What happens if I have too little growth hormone?
Too little growth hormone (deficiency) results in poor growth in children. In adults, it causes a reduced sense of wellbeing, increased fat, increased risk of heart disease and weak heart, muscles and bones. The condition may be present from birth where the cause can be unknown, genetic or due to injury to the pituitary gland (during development or at birth).
Growth hormone deficiency may also develop in adults due to brain injury, a pituitary tumour or damage to the pituitary gland (for example, after brain surgery or radiotherapy for cancer treatment). The main treatment is to replace the growth hormone using injections - either once a day or several times a week.
In the past, growth hormone treatment was stopped at the end of growth. It is now clear that growth hormone contributes to both bone mass and muscle mass reaching the best possible level, as well as reducing fat mass during development to an adult. The specialist is therefore likely to discuss the benefits of continuing growth hormone after growth has completed until age 25 to make sure bone and muscle mass reach the best possible level. Additionally, growth hormone has been linked to a sensation of wellbeing, specifically energy levels. There is evidence that 30-50% of adults with growth hormone deficiency feel tired to a level that impairs their wellbeing. These adults may benefit from lifelong treatment with growth hormone. Taking growth hormone when adult will not result in increased height.
Last reviewed: May 2021
The first step in treating your child is forming an accurate and complete diagnosis. Before a growth hormone deficiency diagnosis can be made, your child's physician may have to rule out other disorders first, including genetic short stature (inherited family shortness), inadequate caloric intake, thyroid hormone deficiency, and other illnesses, including gastrointestinal problems. In addition to learning your child's
complete medical history, gathering information about the heights and any health problems of your relatives, and conducting a physical examination, your child's doctor may: Since growth hormone is produced in bursts, it is unlikely that any single blood sample will provide a definitive diagnosis. If growth hormone deficiency is
suspected, your physician may use a stimulant of growth hormone secretion (which may include vigorous exercise and/or several chemicals and medications), and measure the growth hormone release over time. If growth hormone deficiency is diagnosed, your physician may order an MRI of the brain to look at the hypothalamus and pituitary gland.How we diagnose growth hormone deficiency
After we complete all necessary tests, our experts meet to review and discuss what they have learned about your child's condition. Then we will meet with you and your family to discuss the results and outline the best treatment options.
Researchers are currently working on more efficient and accurate ways of diagnosing growth hormone deficiency.
How we treat growth hormone deficiency
Our physicians are focused on child-centered care, and we're known for our science-driven approach. Our experienced doctors know that growth hormone deficiencies are complex problems that can take different forms from patient to patient. Such an individualized illness may demand several thorough diagnostic tests and treatment specifically tailored to your child.
Typically, treatment of growth hormone deficiency involves receiving regular injections of synthetic human growth hormone, and children receive daily injections. Treatment usually lasts several years, although results are often seen as soon as three to four months after the injections are started.
The earlier treatment for growth hormone deficiency is started, the better chance the child will have of attaining her normal or near-normal adult height. However, not all children respond well to growth hormone treatment.
Children who have mutations that make their cells unresponsive to the growth hormone may be treated with injections of synthetic human IGF-1 instead.
- These injections are reserved for patients who are extremely short and have very low IGF-1 levels, but who passed their growth hormone stimulation testing.
The American Academy of Pediatrics (AAP) recommends that therapy with growth hormone is medically and ethically acceptable for children:
- with classic growth hormone deficiency
- awaiting kidney transplantation who have chronic renal insufficiency
- with Turner syndrome (females)
- whose extreme short stature prohibits their participation in everyday activities and who have a condition that will benefit from growth hormone therapy
How safe is treatment for growth hormone deficiency?
While there are many potential side effects, particularly if growth hormone is used to treat children who don't have a true hormone deficiency, researchers generally agree that treatment with human growth hormone is safe and effective. In 1985, the U.S. Food and Drug Administration (FDA) approved a biosynthetic growth hormone, thus:
- eliminating the risk of disease transmission from human growth hormone (previously, the only source of this hormone had been from the pituitary glands of the deceased)
- creating an unlimited supply of the hormone
Please consult your child's physician for more information.
Growth hormone deficiency may make your child feel insecure or self-conscious, and if appropriate, we can also put you in touch with mental health professionals to help with any negative feelings your child may be experiencing.
Coping and support
We understand that you may have a lot of questions when your child is diagnosed with growth hormone deficiency. How will it affect my child long-term? What do we do next? We've tried to provide some answers to those questions on this site, but there are also a number of other resources to guide you and your family through diagnosis and treatment.
Patient education: From the first office visit, our nurses will be on hand to walk you through your child's treatment and help answer any questions you may have — What is treatment like? Are there any side effects? They will also reach out to you by phone, continuing the care and support you received while at Children's.
Parent to parent: Want to talk with someone whose child has been treated for growth hormone deficiency? We can often put you in touch with other families who can share their experience.
Social work: Our social workers and mental health clinicians have helped many other families in your situation. Your social worker can offer counseling and assistance with issues such as stresses relating to small stature, coping with your child's growth hormone deficiency diagnosis, and dealing with financial difficulties.
On our patient resources pages, you can read all you need to know about:
- getting to Boston Children's
- accommodations
- navigating the hospital experience
- resources that are available for your family