Growth hormone deficiency (GHD), or human growth hormone deficiency, is a medical condition resulting from not enough growth hormone (GH). Generally the most noticeable symptom is that an individual attains a short height. Newborns may also present low blood sugar or a small penis size. In adults there may be decreased muscle mass, high cholesterol levels, or poor bone density.GHD can be present at birth or develop later in life. Causes may include genetics, trauma, infections, tumors, or radiation therapy. Genes that may be involved include GH1, GHRHR, or BTK. In a third of cases no cause is apparent. The underlying mechanism generally involves problems with the pituitary gland. Some cases are associated with a lack of other pituitary hormones, in which case it is known as combined pituitary hormone deficiency. Diagnosis involves blood tests to measure growth hormone levels.Treatment is by growth hormone replacement using synthetic human growth hormone. The frequency of the condition is unclear. Most cases are initially noticed in children. The genetic forms of this disease are estimated to affect about 1 in 7,000 people. Most types occur equally in males and females though males are more often diagnosed. Signs and symptoms
Child
Severe prenatal deficiency of GH, as occurs in congenital hypopituitarism, has little effect on fetal growth. However, prenatal and congenital deficiency can reduce the size of a males penis, especially when gonadotropins are also deficient.
History
Like many other 19th century medical terms which lost precise meaning as they gained wider currency, "midget" as a term for someone with severe proportional shortness acquired pejorative connotations and is no longer used in a medical context.Notable modern pop cultural figures with growth hormone deficiency include actor and comedian Andy Milonakis, who has the appearance and voice of an adolescent boy despite being in his 40s. Argentine footballer Lionel Messi was diagnosed at age 10 with growth hormone deficiency and was subsequently treated. See also
Hypothalamic–pituitary–somatic axis

References
External links
Am Assoc Clinical Endocrinologists - practice guidelines and recommendations for diagnosis and treatment of GH deficiency, reflecting standard practice among U.S. endocrinologists