Defective pituitary secretion of growth hormone (GH) can result from pituitary or hypothalamic tumors, autoimmune pituitary disease, inflammatory disease like sarcoidosis, or from a genetic disorder whereby GH or other pituitary hormones are deficient. GH deficiency is screened for by measurement of a growth factor (insulin like growth factor-one or IGF-1) which is produced by the liver under the action of pituitary GH.
Typical children tend to be short after the first 18 months of life and to grow at an abnormally slow rate after this age. Children with hypopituitarism may appear younger than their chronological age, they have delayed sexual maturation with delayed skeletal development of bone age, and they tend to be overweight for height. Growth hormone therapy is given by a small subcutaneous injection daily at a dose sufficient to normalize the IGF-1 level and attain normal (or better) growth rates. Besides GH, other hormones may be affected, such as the adrenal trophic hormone (ACTH) which can lead to problems such as low blood glucose levels (hypoglycemia), thyroid trophic hormone (TSH) which can lead to thyroid hormone deficiency, gonadotrophic hormones which can lead to low levels of sex hormones and poor sexual development and infertility. In cases induced by tumors, hormones of the posterior pituitary (ADH or vasopressin) can become deficient leading to an inability to concentrate urine (diabetes insipidis).