Growth hormone test results highlight growth deficiencies, reduced pituitary gland function and pituitary tumors. HGH tests include the somatotropin hormone test, growth hormone suppression test, somatomedin C, and growth hormone stimulation test.

Somatotropin test is used to identify HGH deficiency as well as excess. The blood sample for somatotropin test is taken one hour after sleep for more accurate readings. The normal HGH level for men is 5 ng/ml; that for women is less than 10 ng/ml; for children it is 10 ng/ml; and for newborns the range is 10-40 ng/ml. Excess HGH levels indicate gigantism and acromegaly. A decrease in the level indicates HGH deficiency and dwarfism.

Somatomedin C or insulin-like growth factor is considered as the accurate indicator of HGH level in blood. Somatomedin C test is used to detect pituitary abnormalities and acromegaly. The blood test result is not affected by time, activity and diet. The normal test result for HGH level in adults is 42-110 ng/ml. 7-110 ng/ml is the ideal test result for girls in the age group 0 - 8, whereas for boys it is 4-87 ng/ml. For girls in the age group of 9-10 years, the ideal level is 39-186 ng/ml and for boys it is 26-98 ng/ml. In 11-13 age group, normal test result for girls is 66-215 ng/ml and for boys 44-207 ng/ml. An excess level of HGH indicates gigantism and acromegaly.

Growth hormone stimulation test is also known as insulin tolerance or arginine test which checks the body?s ability to produce human growth hormone. A substance known as HGH releasing factor is used for HGH stimulation. In this test, frequent blood samples are taken after injection of insulin. Growth hormone stimulation test gives more accurate results for HGH deficiency. In this test, the normal test result for HGH level is 10 ng/ml. A decrease in HGH levels shows pituitary deficiency.

Growth hormone suppression test is also known as glucose loading test. This test is used to evaluate the excess baseline level of human growth hormone. Two different blood samples are taken in this test. The first sample is taken before giving glucose and the second sample is taken two hours after glucose ingestion. The HGH level is based on the glucose loading. The normal test result for suppressed HGH level is 3 ng/ml. The suppressed base HGH level of 5 ng/ml shows acromegaly syndrome.