Diagnosis and Evaluation of Low Free Testosterone in Men

Clinical Presentation and Diagnosis

The American Diabetes Association recommends measuring free testosterone directly using equilibrium dialysis or calculating it using total testosterone, SHBG, and albumin levels to confirm diagnosis before starting any treatment 1, 2
Symptoms that indicate low free testosterone include sexual symptoms such as decreased libido, erectile dysfunction, and decreased sexual activity 1, 3
Physical symptoms of low free testosterone include loss of muscle mass and strength, increased abdominal fat, decreased energy and endurance, and chronic fatigue 2
Psychological and cognitive symptoms of low free testosterone include depression, decreased motivation, poor concentration, and impaired memory 2

The Endocrine Society recommends measuring total testosterone, SHBG, and free testosterone to evaluate low free testosterone 1, 2
Measuring LH levels can help determine if the low testosterone is primary (testicular) or secondary (pituitary) 2

In obese patients, low total testosterone with normal SHBG is common due to increased conversion of testosterone to estradiol in adipose tissue, leading to a real decrease in free testosterone 4, 2

The diagnosis of low testosterone requires the presence of clinical symptoms and signs, as well as confirmed low free testosterone levels in at least two separate measurements 1, 2, 4

The American Urological Association recommends considering treatment with testosterone replacement therapy if low free testosterone is confirmed in at least two separate measurements 2
Treatment options include transdermal gels or patches, intramuscular injections, and subcutaneous implants 2

The Endocrine Society recommends monitoring testosterone levels after 2-3 months of starting treatment to ensure normal levels are achieved 2