Low testosterone can affect sexual function, energy, mood, muscle and bone health, but symptoms alone cannot diagnose it. A proper assessment combines a relevant symptom pattern, two correctly timed blood tests and investigation of the cause.

Testosterone replacement therapy can help men with confirmed hypogonadism, but it is not a treatment for symptoms or a borderline result in isolation. Safe TRT begins with diagnosis, cause-finding and fertility planning, then continues with individualised treatment and monitoring.

Total testosterone is the usual starting point, but SHBG can make it look lower or higher than the biologically available hormone picture suggests. Calculated free testosterone can clarify selected results, provided the sample, assay and clinical context are sound.

Testosterone results are only useful when the sample is taken under the right conditions and interpreted as part of a hormonal pattern. Timing, fasting, illness, SHBG and repeat testing can change the conclusion.

Testosterone often changes with age, but there is no single age chart that decides whether a man has testosterone deficiency. A useful interpretation separates population ranges from clinical thresholds and considers symptoms, testing conditions, SHBG and the reason for the result.