Low testosterone can be diagnosed by an assessment of symptoms and a blood test to measure testosterone levels. The symptom most associated with low testosterone is reduced sex drive (low libido), however your doctor will ask about a range of symptoms.
How to diagnose hypogonadism in men?
The symptoms of hypogonadism may vary from individual to individual. In late-onset hypogonadism many symptoms resemble those of aging and as a consequence this condition is often undiagnosed. Various diagnostic procedures are available to confirm hypogonadism in a patient who presents with symptoms or signs of testosterone deficiency. These include:
Repeat measurement of morning total testosterone (when levels of serum testosterone can be expected to be higher because of the diurnal rhythm of testosterone) using a reliable assay is recommended by international professional societies in the field as the most widely accepted parameter to establish the presence of hypogonadism in combination with consistent symptoms and signs. In some men, determination of free or bioavailable testosterone may be appropriate.1,2
Values for normal testosterone ranges vary among laboratories depending on the commercial assay employed, and local values should be consulted when a diagnosis of hypogonadism is considered. There is no generally accepted lower limit of normal.
250 pmol/L (72 pg/mL)
A morning testosterone concentration in the blood of 12-35 nmol/L or free testosterone levels above 250 pmol/L (72 pg/mL) can be considered normal.There is general agreement that no testosterone treatment is required.
< 12-35 nmol/L
180 pmol/L (52 pg/mL)
The European Association of Urology (EAU), International Society for the Study of the Aging Male (ISSAM), International Society of Andrology (ISA), European Academy of Andrology (EAA) and American Society of Andrology (ASA) suggest that serum total testosterone levels below 8 nmol/L (231 ng/dL) or free testosterone below 180 pmol/L (52 pg/mL) require testosterone replacement therapy.
In addition, concentrations of the pituitary hormones can be measured. They provide information as to whether the testosterone deficiency is due to disorders of testicular function or of the hypothalamic-pituitary system.
Since symptoms of testosterone deficiency become manifest between 8 and 12 nmol/L (231–346 ng/dL), trials (3– >6 months) of treatment can be considered in men with a clinical picture of testosterone deficiency and borderline testosterone levels when alternative causes of these symptoms have been excluded.1,2
Please consult guidelines relevant to your country of practice as country-specific differences in the diagnosis and treatment of hypogonadism exist.
The benefits of testosterone replacement
The benefits of testosterone replacement on sexual function, fat and lean body mass and bone density in men with low testosterone are clear. The potential benefits of testosterone replacement in reducing the risk of cardiovascular disease, metabolic syndrome and diabetes are still being investigated.
- Controls sexual function (sex drive, erectile function, orgasm)
- Reduces lower urinary tract symptoms (LUTS)
- Increases muscle mass
- Increases strength
- Decreases overall body fat mass
- Decreases belly (visceral) fat mass
- Increases bone mineral density
Health and well-being – quality of life
- Bhasin S, Cunningham GR, Hayes FJ, et al. Testosterone therapy in adult men with androgen deficiency syndromes: an endocrine society clinical practice guideline. J Clin Endocrinol Metab 2006; 91(6): 1995-2010. Return to content
- Wang, C., E. Nieschlag, R. Swerdloff, et al. Investigation, treatment and monitoring of late-onset hypogonadism in males: ISA, ISSAM, EAU, EAA and ASA recommendations. Eur J Endocrinol 2008, 159(5): 507-514. Return to content