The Endocrine Society guideline contains a recommendation that is routinely passed over: in men determined to have androgen deficiency, obtain additional diagnostic evaluation to ascertain the cause.[1]
That instruction distinguishes two clinically different situations wearing the same lab result.
Organic hypogonadism. A structural or disease process affecting the testes or the pituitary. The deficiency is the primary problem.
Functional hypogonadism. Suppression of a fundamentally intact axis by something else — obesity, chronic illness, medications, severe systemic stress. The low testosterone is a consequence.
Why the distinction changes the plan
Because in the functional case there is a driver, and it may be treatable.
Obesity is the clearest example. Adipose tissue converts testosterone to estradiol via aromatase and alters SHBG, and the androgen–obesity relationship is well described.[2] A 2018 review of hypogonadism and male obesity is titled around its unresolved questions,[3] which is an honest signal that the field does not yet know how much of this reverses with what intervention.
Other contributors are more clear-cut. Opioids and glucocorticoids suppress production directly. Untreated obstructive sleep apnea, poorly controlled diabetes and significant chronic illness all affect the axis.
Treating the testosterone number without touching any of that treats a readout.
Why it gets skipped
Because it is the step that can end with "you don't need this."
The confirmation draw and the cause investigation both sit before the prescription, and both can conclude that treatment is not indicated. A process optimised for throughput has the least incentive to run them — which is why they are the two checks worth asking any provider about specifically. See online or in-person TRT.
What good practice looks like here
Confirm first. Repeat the fasting morning total testosterone before concluding anything.[1]
Look for the cause. Pituitary hormones help distinguish a testicular problem from a signalling one, and the history covers medication, sleep, weight and illness.[1]
Address modifiable drivers alongside, not instead. For a man who genuinely meets the criteria, treatment and cause-management are not alternatives.
Screen the contraindications. Fertility plans, elevated hematocrit, untreated severe sleep apnea, recent myocardial infarction or stroke, and the rest of the list.[1]
Frequently asked questions
Is functional hypogonadism "real"? The low level is real and the symptoms are real. What differs is that a driver exists which may respond to treatment of its own.
Will treating my weight fix my testosterone? The relationship is documented; the intervention questions remain explicitly unresolved.[3] See the bidirectional trap.
Should I refuse TRT until the cause is found? Not a decision to make unilaterally — but the cause investigation is a guideline recommendation,[1] and asking whether it has been done is entirely reasonable.
Next in this series
If the cause matters, so does the panel that finds it.
Continue with the lab work that matters.
References
3 sources
- Bhasin S, Brito JP, Cunningham GR, et al. Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2018;103(5):1715–1744. doi:10.1210/jc.2018-00229 · PMID 29562364
- Allan CA, McLachlan RI. Androgens and obesity. Curr Opin Endocrinol Diabetes Obes. 2010;17(3):224–232. doi:10.1097/MED.0b013e3283398ee2 · PMID 20418719
- Grossmann M. Hypogonadism and male obesity: Focus on unresolved questions. Clin Endocrinol (Oxf). 2018;89(1):11–21. doi:10.1111/cen.13723 · PMID 29683196
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