Low testosterone and “subclinical hypogonadism”: what do the results mean?

Testosterone contributes to sexual function, muscle and bone health, and other body processes. A man may wonder about testosterone when he notices a change in libido, energy or strength. Those symptoms deserve attention, but they have many possible causes. A blood result below a laboratory range does not, by itself, establish testosterone deficiency or mean that testosterone treatment will help.[1–3]

Is “subclinical hypogonadism” a hidden disease?

The term can be confusing. In specialist literature, compensated or subclinical hypogonadism may describe normal testosterone with an elevated luteinising hormone (LH). LH is the signal from the pituitary gland that stimulates the testes to make testosterone. The clinical significance of this laboratory pattern is uncertain; it should not be described as a predictable early stage that inevitably leads to complications.[2]

Established male hypogonadism is a clinical syndrome involving compatible symptoms or signs together with consistently low testosterone on appropriately collected tests. Some men have subtle symptoms, but fatigue, irritability and poor concentration are not specific to testosterone deficiency. Recent Endocrine Society guidance cautions against routine testosterone screening in men without symptoms and against applying vague “age-related” labels without a careful diagnosis.[1–3]

When might testosterone deficiency be considered?

A persistent reduction in sexual desire, fewer spontaneous morning erections, erectile difficulties, reduced body hair, small testes, loss of strength, infertility, unexplained anaemia or low-trauma fractures can prompt a clinician to consider testosterone deficiency. No one symptom proves it, and erectile dysfunction often has vascular, psychological, medication-related or other causes.[2, 3]

Potential causes include a disorder of the testes (primary hypogonadism) or of the hypothalamus or pituitary gland (secondary hypogonadism). Obesity, type 2 diabetes, chronic illness, sleep problems and medicines such as opioids or glucocorticoids may also be associated with lower measured testosterone. Acute illness can temporarily affect a test result. The aim is to find and address the cause rather than assume that a symptom is due to normal ageing or that testosterone is the answer.[1–3]

How is it investigated?

Assessment starts with the person’s symptoms, medical history, medicines, sleep, fertility plans and an examination when indicated. A clinician generally orders two separate early-morning testosterone tests, preferably fasting and when the person is otherwise well. Testosterone changes across the day, and assays and reference ranges vary. A single borderline result should be interpreted cautiously.[1–3]

LH and follicle-stimulating hormone (FSH) help distinguish testicular from pituitary or hypothalamic causes. Depending on the circumstances, a clinician may assess prolactin, other pituitary hormones, thyroid function, blood count or iron studies. Free testosterone may be helpful in selected cases when total testosterone is borderline or the protein that binds testosterone is altered; it is not an automatic replacement for a reliable total testosterone test. Further investigations, such as pituitary imaging or bone density assessment, are guided by the clinical findings.[2, 3]

A normal testosterone result with raised LH is not the same as confirmed low testosterone. It may warrant review in context, but there is no established reason to prescribe testosterone solely to “treat the number.”[2]

Does a borderline result predict future disease?

Confirmed, longstanding testosterone deficiency can affect bone density, body composition and sexual function. However, it is misleading to state that everyone with a borderline measurement or a compensated laboratory pattern will develop osteoporosis, diabetes or heart disease.[2]

Low testosterone is often found alongside obesity or poor health, but an association does not show that low testosterone caused a cardiovascular or metabolic condition. Likewise, testosterone treatment should not be offered as a way to prevent heart disease or treat diabetes. Benefits and risks depend on the person’s diagnosis and circumstances.[1, 3]

What can be done first?

If obesity, poor sleep, a medicine or another health condition may be contributing, addressing that issue is often a useful first step. A manageable programme of physical activity, including resistance exercise, a balanced diet and treatment of sleep problems can support overall health. These steps are valuable whether or not testosterone increases; they are not guaranteed to correct an underlying testicular or pituitary disorder. In men with obesity-related hypogonadism and no other identified cause, the Endocrine Society describes weight loss as the usual first-line approach.[1]

If low libido, fatigue or mood symptoms persist, assessment should also consider depression, sleep apnoea, relationship factors, diabetes, anaemia and other possible causes. The plan should follow the findings rather than a generic “testosterone boost” programme.[1–3]

When is testosterone treatment considered?

Testosterone replacement may be appropriate for a man with confirmed hypogonadism, clinically important symptoms and a discussion of likely benefits, uncertainties, alternatives and monitoring. An Australian registered product’s indication requires deficiency to be confirmed by clinical features and biochemical tests. Treatment is not routinely recommended for an otherwise well man because of age, a single borderline test or vague symptoms alone.[1, 3, 4]

Testosterone can suppress sperm production and may compromise fertility. Men planning children should discuss this before starting therapy; fertility-preserving management may require specialist input. Assessment before treatment also considers the blood count, prostate concerns, sleep apnoea, cardiovascular history and other conditions. Follow-up includes symptoms, testosterone level, haematocrit and prostate assessment as appropriate.[2, 3, 5]

The safety picture is nuanced. A large trial did not find a meaningful increase in heart attack or stroke over roughly one to four years in the men studied, but reported more pulmonary embolism and fractures in the testosterone group; long-term safety remains uncertain. Those findings do not justify declaring therapy either universally safe or universally harmful.[1]

The main message

If symptoms concern you, discuss them with your GP. A thoughtful assessment can identify testosterone deficiency when it is present and uncover other causes when it is not. “Subclinical hypogonadism” is not a reliable label for every man with tiredness or a borderline blood test. Treatment decisions should be based on a clear diagnosis and personal goals, especially future fertility.[1–3]

This article is general information, not an individual diagnosis or treatment recommendation. Do not start, stop or change prescribed hormones without advice from your treating clinician.

References

1. Endocrine Society. Statement on Testosterone Replacement Therapy, 2026.
2. European Association of Urology. Sexual and Reproductive Health Guidelines: Male Hypogonadism.
3. Endocrine Society. Testosterone Therapy in Men With Hypogonadism: Clinical Practice Guideline.
4. Therapeutic Goods Administration. ANDROFORTE 5 registration and approved indication.
5. Healthy Male. Androgen deficiency clinical summary guide.