Testosterone is one of a group of hormones known as androgens. It is the primary sex hormone produced by males and is important in the regulation of the sex drive and development of primary and secondary sex characteristics.
'Urogenital' refers to something that has both urinary and genital origins, and is used because the urinary and reproductive systems of males merge. The male urogenital system consists of several parts, including the testes, urethra, penis and prostate.
A testosterone test is a test which measures the amount of testosterone in a person's blood or saliva. It is usually used when a health condition affecting testosterone levels is suspected. The conditions for which a testosterone test may be used as a diagnostic tool differ between men and women.
Male hypogonadism is a disorder in which a man produces abnormally low levels of testosterone. Testosterone deficiency often results in symptoms such as reduced sex drive and infertility, which can also affect a man's self esteem and his overall sense of well-being.
Testosterone deficiency, diabetes and metabolic syndrome
The association between low levels of testosterone and type 2 diabetes mellitus are well recognised. Metabolic syndrome is a condition characterised by several co-occurring metabolic imbalances (e.g. impaired insulin metabolism, obesity, high blood pressure); it often precedes type 2 diabetes mellitus, and is also associated with testosterone deficiency.
The aim of testosterone replacement therapy is to increase blood testosterone concentrations to normal levels. In doing so, it can also restore a man's sex drive and expression of male sex characteristics (e.g. deep voice, body hair).
In males over 40 years of age, testosterone deficiency is sometimes called late-onset hypogonadism, andropause or male menopause. Testosterone deficiency in ageing men is caused by a natural reduction in testosterone production as a man ages.