Growth Hormone

Growth hormone is a protein made by your pituitary gland that helps regulate growth, body composition, and metabolism. It acts on many tissues and also triggers the liver to make insulin-like growth factor 1, which carries many of its growth effects.

Because growth hormone is released in short bursts, levels in the bloodstream rise and fall during the day and night. A growth hormone test measures the amount in your blood at a specific time and may be done as part of special stimulation or suppression procedures. Your clinician often interprets it together with other tests and your symptoms.

Checking growth hormone helps evaluate slow growth in children, possible deficiency in adults, or suspected excess when symptoms suggest acromegaly. It can also be used to monitor treatment after pituitary surgery or medical therapy.

Too little growth hormone can affect height in children and can influence energy, muscle mass, and bone health in adults. Too much can cause changes in facial features and hands, joint pain, headaches, and metabolic issues. Your clinician uses this test, often with insulin-like growth factor 1 and dynamic testing, to clarify the cause and guide care.

A single growth hormone result is only one piece of the picture because levels change with sleep, meals, stress, and exercise. Your clinician will interpret your result in context, including the time of blood draw, recent activity, medicines, and other lab results such as insulin-like growth factor 1.

If deficiency is suspected, results may be assessed during a stimulation test. If excess is suspected, results may be assessed during a suppression test. If findings do not match your symptoms, your clinician may repeat testing, use a different assay, or order imaging of the pituitary. Ask about next steps, including follow-up testing and how to prepare so results are as accurate as possible.