Measurements of testosterone are used in the diagnosis and treatment of disorders involving the male sex hormones (androgens), including primary and secondary hypogonadism, delayed or precocious puberty, impotence in males and in females hirsutism (excessive hair) and virilization (masculinization) due to tumors, polycystic ovaries and adrenogenital syndromes. Testosterone is synthesized almost excelusively by the Leydig cells or the testes and promotes the development of the seondary sex characteristics in men and serves to maintain the function of the prostate and seminal vesicles. In women, small quantities are formed in the ovaries. In physiological concentrations, androgens have no specific effects in women. Increased production of testosterone in women can cause virilizaton (depending on the increase).