Male hypogonadism is a clinical syndrome caused by a failure of the testes to produce adequate levels of testosterone that are needed for the normal growth and development of a male. The condition may be congenital or may develop later in life.
Hypogonadism can be classified into primary and secondary hypogonadism. Primary hypogonadism may be due to testicular failure that refers to any dysfunction of the testicles which interrupts the normal hormone production. The common causes of primary hypogonadism include Klinefelter syndrome, which is a congenital abnormality of the sex chromosomes (an extra X chromosome) causing abnormal development of the testicles. Other causes of primary hypogonadism include undescended testicles, mumps orchitis, hemochromatosis, testicular injury, chemotherapy and radiotherapy.
Secondary hypogonadism may result from a dysfunctioning of the hypothalamus or pituitary gland that interrupts their normal functions. Certain conditions such as Kallmann syndrome (abnormal development of the hypothalamus), pituitary disorders, inflammatory diseases, HIV, certain medications, obesity and normal aging may also result in hypogonadism.
The symptoms of hypogonadism generally depend on the age of the affected individual. During fetal development it may result in impaired growth or underdevelopment of external male or ambiguous genitals. The symptoms during pre-puberty include impaired growth of external male genitals, improper distribution of body hair, decreased muscle mass, gynecomastia or development of breast tissues, lack of deepening of the voice and disproportional growth of arms and legs in relation to the trunk of the body. Certain symptoms such as erectile dysfunction, infertility, lack of facial or body hair, reduced muscle mass and gynecomastia may be seen in adult patients. Sometimes affected individuals may experience emotional and mental disturbances, fatigue, and loss of libido, hot flushes and lack of concentration.
The diagnosis of male hypogonadism includes medical history, physical examination and laboratory investigations. Other tests such as estimation of hormonal levels, semen analysis, pituitary imaging, testicular biopsy and other genetic studies may be used to diagnose the underlying causes of the disorder.
Hormone replacement therapy is the most common approach for the management of male hypogonadism. Testosterone replacement therapy can be used in young as well as adult patients. Testosterone replacement therapy is useful for restoring sexual function, muscle and bone strength as well as to provide a sense of wellbeing in adult patients. In young patients it stimulates puberty and the development of secondary sexual characteristics.