Growth hormone (GH) testing measures the level of human growth hormone in the blood. GH is a hormone made in the pituitary gland in the head. Your doctor may order one of the following tests if you have symptoms that suggest a GH abnormality:

  • Suppression test—measures the amount of GH that is produced when the pituitary gland is told not to produce any GH
  • Stimulation test—measures the function of the pituitary gland to secrete GH when it is told to secrete GH

There are many factors that can interfere with GH testing. Stress, exercise, certain medications, and blood glucose levels can all cause GH levels to rise and fall. For this reason, GH tests are often done with other hormones, like insulin-like growth factor-1 ( IGF-1).

Suppression tests are ordered:

  • For children who show symptoms of gigantism
  • For adults who show signs of acromegaly, a condition marked by abnormally large bone growth
  • To check for abnormalities in the function of the pituitary gland
  • If a tumor in the pituitary gland is suspected—This is done with another test called IGF-1 that does not vary so much over time.
  • To monitor the effectiveness of GH replacement (commonly done with IGF-1 test)

GH stimulation tests are ordered:

  • For children who are significantly short for their age
  • When thyroid testing rules out a problem with the thyroid but growth is slower than expected
  • To check for abnormalities in the function of the pituitary gland
  • For children who have had radiation therapy
  • For children whose bones are not developing normally
  • For adults with symptoms of muscle weakness, lack of energy, thin skin, weak bones, and other symptoms that when taken together, suggest a lack of GH
  • For adults with pituitary disorders that increase the risk of growth hormone deficiency

Delayed Growth
Stunted Growth Child
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