Feature Article

Androgen deficiency in men

Carolyn A Allan, Rob McLachlan



Presentations of androgen deficiency may be subtle, therefore it is important that the diagnosis is actively considered. Testosterone therapy is highly effective for younger men with established androgen deficiency, but its role in older men is less clear.

Key Points

  • The presentation of androgen deficiency may be subtle, therefore the diagnosis needs to be actively considered in the appropriate clinical context.
  • Klinefelter’s syndrome is the most common cause of primary hypogonadism. Secondary hypogonadism is caused by hypothalamo-pituitary disorders such as pituitary tumours (especially prolactinoma) and iron overload disorders such as haemochromatosis and thalassaemia.
  • Serum total testosterone is the best method for assessing androgenic status. Calculated free testosterone values correlate well with actual free testosterone, but no published population-based reference ranges exist. Therefore calculated free testosterone levels must be interpreted with caution.
  • A low serum LH in the presence of low testosterone raises the possibility of secondary hypogonadism. Investigation may involve assessment of prolactin, anterior pituitary hormones and iron levels.
  • The benefits of treatment in testosterone-deficient men are well established. Clinical responses to treatment are important in determining the dose and frequency of testosterone replacement therapy.
  • The treatment of symptomatic ageing men with borderline serum testosterone levels remains controversial, with the benefits and risks of testosterone therapy largely unknown.