The Growth Hormone (GH) test contains 1 test with 1 biomarker.
Description: The Growth Hormone (GH) test is a laboratory test that measures the level of growth hormone in the blood. Growth hormone is a peptide hormone produced by the pituitary gland, located at the base of the brain. It plays a crucial role in regulating growth, metabolism, and body composition.
Also Known As: GH Test, Growth Hormone GH, HGH Test, Human Growth Hormone (hGH), Somatotropin, Growth Hormone Stimulation Test
Collection Method: Blood Draw
Specimen Type: Serum
Test Preparation: Patients should be fasting and have rested for at least 30 minutes prior to collection.
When is a Growth Hormone test ordered?
A Growth Hormone test may be ordered in the following situations:
Evaluation of Growth Disorders: In children, a Growth Hormone test is often ordered when there are concerns about growth failure or abnormal growth patterns. It helps assess if the pituitary gland is producing adequate levels of growth hormone and aids in diagnosing growth hormone deficiency or excess.
Diagnosis of Pituitary Disorders: The test may be ordered to investigate suspected pituitary gland dysfunction or tumors affecting the production of growth hormone.
Monitoring Growth Hormone Replacement Therapy: For individuals with growth hormone deficiency who are undergoing growth hormone replacement therapy, regular testing is necessary to ensure optimal dosing and response to treatment.
What does a Growth Hormone blood test check for?
Growth hormone is a hormone that is necessary for children's appropriate growth and development. From birth to adolescence, it promotes correct linear bone growth. Growth hormone regulates the rate at which the body produces energy from meals as well as lipids, proteins, and glucose in both children and adults. It also aids in the regulation of red blood cell formation and muscle mass.
The pituitary gland, a grape-sized gland behind the bridge of the nose at the base of the brain, produces growth hormone. It's released into the bloodstream in pulses throughout the day and night, with maxima occurring largely at night. As a result, a single measurement of GH in blood is difficult to interpret and is rarely relevant in clinical practice. If the sample is collected during a pulse, the value will be higher; if it is taken between pulses, the value will be lower. As a result, GH stimulation and suppression tests are frequently employed to detect GH anomalies.
GH insufficiency is a condition in which the body does not produce enough of
Insufficient GH production causes children to grow more slowly and to be smaller for their age. Some children are born with GH shortage, but others may develop a shortfall later in life as a result of a brain injury or tumor. These disorders can damage the pituitary gland, resulting in a reduction in pituitary function and decreased pituitary hormone production. The cause of a deficit is sometimes unknown.
Growth hormone is involved in the regulation of bone density, muscular mass, and glucose and lipid metabolism in adults. It can also have an impact on the heart and kidneys. Deficiencies might start in childhood or emerge later in life. Damage to the pituitary gland from a head injury, a brain tumor, surgery, or radiation treatment, for example, might create a deficit. Pituitary hormones may be reduced as a result of this. A GH deficit can cause a loss of bone density, muscle mass, and lipid levels to change. Adults with decreased bone density and/or muscle strength, as well as elevated lipids, are not routinely tested for GH insufficiency. These illnesses are caused by GH deficiency, which is a fairly unusual cause.
A GH-secreting pituitary tumor is the most common cause of excessive GH. Surgically removing the pituitary tumor that is producing the excess and/or treating it with medicines or radiation are frequently options. In most situations, GH and IGF-1 levels will revert to normal or near normal levels as a result of this.
In youngsters, too much GH can cause their long bones to continue to develop past puberty, culminating in gigantism, a rare disorder characterized by heights of 7 feet or more. Excess GH can cause face thickness, general weakness, delayed puberty, and headaches in those who have it.
Excess GH in adults can cause acromegaly, an uncommon disorder characterised by bone thickening rather than bone lengthening. Increased GH levels can lead to bigger hands and feet, expanded facial bones, carpal tunnel syndrome, and abnormally enlarged internal organs, despite symptoms like skin thickening, sweating, weariness, headaches, and joint discomfort being modest at first. Skin tags and intestinal polyps can also be caused by too much GH.
If neglected, acromegaly and gigantism can result in type 2 diabetes, a higher risk of high blood pressure, cardiovascular disease, arthritis, and, generally, a shorter lifespan.
Lab tests often ordered with a Growth Hormone test:
- Growth Hormone Releasing Hormone
- Free T3
- Free T4
- IGF BP-3
Conditions where a Growth Hormone test is recommended:
A Growth Hormone test may be required in the following conditions or situations:
Growth Hormone Deficiency: Children who exhibit significant growth failure or delayed puberty, or adults with symptoms suggestive of growth hormone deficiency, such as decreased bone density or decreased muscle mass, may require a Growth Hormone test.
Acromegaly: Adults with enlarged body parts, facial changes, joint pain, or other symptoms associated with excessive growth hormone production may require a Growth Hormone test to confirm the diagnosis.
How does my health care provider use a Growth Hormone test?
Growth hormone testing is frequently done as a follow-up to other aberrant pituitary hormone test results in order to diagnose growth hormone insufficiency and evaluate pituitary gland function.
GH testing is also used to detect excess GH and to diagnose and track acromegaly and gigantism treatment.
Growth hormone is required for appropriate development and growth in children, as well as for the regulation of metabolism in both children and adults. GH is produced by the pituitary gland and released into the blood in pulses throughout the day.
Because growth hormone is released in pulses, a single blood level measurement is rarely useful in clinical practice. As a result, it's common to do tests to see if the pituitary is suppressing or stimulating growth hormone secretion.
GH stimulation tests are used to identify hypopituitarism and GH insufficiency. A sample of blood is collected after 10-12 hours of fasting for a stimulation test. The person is then given an intravenous solution of a chemical that generally stimulates the production of GH from the pituitary under under medical supervision. Blood is obtained at regular intervals and GH levels are measured to evaluate if the pituitary gland was stimulated to produce the desired levels of GH. The most common stimulant is arginine, but clonidine and glucagon are also utilized. Vigorous exercise, which generally induces an increase in GH, could be employed as a GH release stimulant.
GH suppression tests aid in the detection of GH excess. A blood sample is drawn after 10-12 hours of fasting for a suppression test. A standard glucose solution is then given to the person to drink. Blood samples are taken at regular intervals and examined for GH to evaluate if the glucose dose has suppressed the pituitary gland adequately.
Insulin-like growth factor-1 is produced in response to growth hormone. IGF-1 is a hormone that helps promote appropriate bone and tissue growth and development by mediating the effects of GH. Unlike GH, however, its blood level remains constant throughout the day. As a result, IGF-1 is a good indication of average GH levels, and the IGF-1 test is frequently used to diagnose GH shortage or excess.
A GH suppression test and IGF testing can also be used to track how well a GH-producing pituitary tumor is responding to treatment. If a tumor is found, the levels of GH and IGF-1 can be evaluated after it is removed to see if the tumor was completely eliminated. For years following, tests may be required at regular intervals to monitor GH production and detect tumor recurrence.
Prolactin, free T4, TSH, cortisol, FSH, LH, and testosterone are some of the other blood tests that can be used to assess pituitary gland function. These tests are routinely done before GH testing to ensure that they are normal and/or under control with medication before GH testing. Hypothyroidism, for example, must be treated before GH deficiency testing in children; otherwise, a falsely low GH result may be seen.
What do my growth hormone test results mean?
If the person has signs and symptoms of GHD and their GH levels are not significantly stimulated after a GH stimulation test, it is likely that they have a GH deficiency that the health practitioner can treat.
Thyroid issues can induce symptoms similar to GHD, therefore if the person's TSH and/or T4 levels are abnormal, it will likely be addressed first. Hypopituitarism and/or a general decline in pituitary function are also possible. GH deficiency tests should not be done until a person's thyroid function has been assessed. If a child has hypothyroidism, the condition should be addressed and the child's growth rate assessed before GH testing is considered.
If a person engages in rigorous exercise but does not see a rise in GH levels, they may have a GH deficiency. This discovery would need to be followed up with more testing.
Most Common Questions About the Growth Hormone test:
Understanding the Growth Hormone Test
What is the Growth Hormone test?
The Growth Hormone (GH) test is a blood test that measures the level of growth hormone in the blood. Growth hormone is produced by the pituitary gland and is essential for growth in children and for metabolic processes in adults.
Why is the Growth Hormone test performed?
The GH test is usually performed to evaluate pituitary function and diagnose conditions related to abnormal growth hormone levels. It may be used to help diagnose growth hormone deficiency or excess, conditions that can cause growth disorders in children or metabolic disorders in adults.
Interpreting Growth Hormone Test Results
What do high Growth Hormone test results mean?
High levels of growth hormone may suggest a condition called acromegaly (in adults) or gigantism (in children), both of which are often due to a noncancerous tumor in the pituitary gland. High GH levels can also be due to extreme stress, intense exercise, or low blood sugar levels.
What do low Growth Hormone test results mean?
Low levels of growth hormone may indicate growth hormone deficiency. This can lead to delayed growth and shorter stature in children and altered body composition in adults, with increased fat and decreased muscle mass.
What is a normal range for the Growth Hormone test?
Growth hormone levels can vary widely, depending on factors such as age, sex, time of day, and activity level. Normal ranges can be anywhere from 0 to 10 ng/mL, but specific ranges may vary by laboratory.
Growth Hormone Test and Growth Disorders
How does the Growth Hormone test relate to dwarfism?
Dwarfism is often associated with a deficiency of growth hormone. If a child has symptoms suggestive of dwarfism, such as slow growth and shorter stature, a GH test might be ordered to evaluate for possible growth hormone deficiency.
How is the Growth Hormone test used in relation to gigantism and acromegaly?
Gigantism in children and acromegaly in adults are typically caused by an overproduction of growth hormone, usually due to a pituitary tumor. A GH test is often used to confirm these diagnoses.
Growth Hormone Test and Other Conditions
Can the Growth Hormone test be used to assess pituitary function?
Yes, the GH test is one of several tests that can be used to assess pituitary function. The pituitary gland produces several hormones, including growth hormone, and abnormalities in these hormone levels can indicate a pituitary disorder.
Can the Growth Hormone test help diagnose metabolic disorders?
Yes, in adults, growth hormone plays a role in body composition, including fat distribution and muscle mass, and abnormal levels can be associated with metabolic disorders like obesity or muscle wasting.
Can the Growth Hormone test help diagnose hypopituitarism?
Yes, hypopituitarism, a condition in which the pituitary gland doesn't produce enough of certain hormones, can lead to lower than normal levels of growth hormone. The GH test can help in the diagnosis of this condition.
Growth Hormone Test and Treatment Monitoring
How is the Growth Hormone test used to monitor treatment in people with growth disorders?
For individuals receiving growth hormone therapy, regular GH tests are used to monitor the effectiveness of the treatment and to adjust the dosage as needed.
How often should the Growth Hormone test be performed in someone receiving growth hormone therapy?
The frequency of testing will depend on the individual's specific circumstances, such as the severity of the condition, the response to treatment, and the treating physician's judgement. It could range from every few months to once a year.
How does changes in lifestyle or diet affect the results of a Growth Hormone test?
Physical stress, malnutrition, and severe obesity can potentially affect GH levels. Regular exercise may increase GH production, while high-sugar foods may decrease GH secretion.
Growth Hormone Test and Other Tests
How does the Growth Hormone test relate to the Insulin-like Growth Factor-1 (IGF-1) test?
IGF-1 is a hormone that is regulated by growth hormone, and its levels are more stable and reflective of average GH levels. Doctors often order the two tests together because they can give complementary information.
Why might the Growth Hormone test be ordered with an MRI scan?
If GH levels are abnormally high, an MRI may be ordered to visualize the pituitary gland and check for the presence of a tumor.
Are there any medications that can interfere with the Growth Hormone test results?
Yes, various medications can affect the results of the GH test, including oral contraceptives, insulin, and certain steroids.
Can pregnancy affect the results of the Growth Hormone test?
Pregnancy can potentially increase GH levels, and this should be taken into account when interpreting test results.
Can illness or stress affect the results of a Growth Hormone test?
Yes, acute illness or severe stress can temporarily increase GH levels.
What is the difference between the Growth Hormone test and the Growth Hormone Stimulation test?
The Growth Hormone test measures the level of GH in the blood at a single point in time, while the Growth Hormone Stimulation test measures the body's ability to produce GH in response to specific stimuli.
What other tests might be performed alongside the Growth Hormone test?
Other tests that may be performed include tests for other pituitary hormones (like TSH, ACTH, and LH), IGF-1, and imaging tests like MRI to evaluate the pituitary gland.
Can the Growth Hormone test be used to detect pituitary tumors?
Yes, elevated GH levels can suggest the presence of a pituitary tumor, which would typically be confirmed with imaging tests.
How does sleep affect the results of a Growth Hormone test?
GH secretion is increased during sleep, especially during deep sleep. This is why, in some cases, a series of GH tests may be done through the night to evaluate GH secretion patterns.
Can the Growth Hormone test be used in conjunction with genetic testing?
In some cases, if an inherited growth disorder is suspected, the GH test can be used in conjunction with genetic testing to confirm a diagnosis.
Can the Growth Hormone test help detect issues with bone age?
GH plays a crucial role in bone growth, and GH deficiency can lead to delayed bone age. If a child has symptoms of slow growth, a GH test, along with a bone age study, may be performed.
Can a Growth Hormone test be performed on a newborn?
GH testing is not typically performed on newborns. However, if there are symptoms suggestive of a severe deficiency of pituitary hormones (like hypoglycemia), GH testing may be considered.
We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.