Human growth hormone is produced by cells called somatotrophs in the anterior lobe of the pituitary gland. Neurons in the hypothalamus produce growth hormone releasing hormone, which stimulates the cells in the anterior pituitary to synthesize HGH.
Disorders of growth hormone synthesis are relatively uncommon; however, the results may be drastic. Pituitary tumors that secrete excess HGH during childhood can lead to a disorder called gigantism. People with this condition grow to heights of 7 feet or taller and develop coarse facial features. Conversely, people with growth hormone deficiency have a short stature and often grow less than 5 feet tall without supplemental injections of HGH.
The anterior pituitary gland also manufactures many other hormones that regulate the function of the endocrine system. These include thyroid stimulating hormone, follicle stimulating hormone, luteinizing hormone, adrenocorticotropic hormone, melanocyte stimulating hormone, and prolactin.