Diagnosis
Low-T Symptoms: Seven Signals That Actually Warrant a Blood Test
The internet will tell you every minor grievance is a testosterone problem. The evidence is narrower. Here are the symptoms clinicians actually treat as red flags worth testing for.
The symptom list in most TRT clinic adverts runs to about twenty items. Some of them are genuine hormone-related flags. Most are "things that happen to men in their forties" and have nothing to do with testosterone.
Here are the seven symptoms that the major clinical guidelines - Endocrine Society, BSSM, EMAS - consistently treat as serious enough to warrant a proper hormone panel. If more than one or two are present and persistent, an early-morning total testosterone test is warranted.
1. Loss of morning erections
This is the single most reliable clinical marker. A healthy man typically wakes with a physiological erection several mornings a week, reflecting overnight testosterone cycling. A persistent, months-long absence of morning erections - not occasional, not "because I'm stressed" - is one of the first things an endocrinologist will ask about.
This is not the same as erectile dysfunction during sex, which has many other causes (vascular, psychological, medication). The overnight/morning signal is hormonal.
2. Persistent loss of libido
Not occasional flatness. Not "my partner and I are in a rough patch." A sustained, unexplained collapse in interest in sex - over months, not weeks - across contexts that previously would have produced desire.
Libido is notoriously multi-factorial (relationships, stress, sleep, medication), which is why clinicians take it seriously combined with other markers rather than in isolation.
3. Fatigue that sleep does not fix
The signal here is fatigue that persists despite adequate sleep - seven-to-eight hours, decent quality, in a dark cool room. If you're running on five hours a night, the problem is probably not testosterone.
Chronic, unexplained fatigue in the presence of normal thyroid, normal B12, normal iron, and no obvious lifestyle cause is a relevant signal.
4. Loss of muscle mass or strength despite training
Men generally do not lose muscle when they are training consistently and eating adequate protein. When that's true and strength is falling anyway - the weights you could hit six months ago suddenly feel impossible - hormone status becomes a relevant question.
This is different from "I can't gain muscle as fast as when I was 22" (normal) or "I haven't trained in six months and I'm weaker" (causal).
5. Gynecomastia or breast tenderness
New breast tissue development or persistent tenderness in adult men is not a normal finding. It can reflect an oestradiol-to-testosterone ratio that has shifted, either because testosterone has fallen or because something else is elevated. Either way, it warrants investigation.
6. Mood: a specific kind of low
Not depression in the clinical sense - though hypogonadism can mimic it. The signal clinicians flag is a specific pattern: low motivation, flattened affect, loss of drive, irritability, and loss of the "drive to show up" that is typically characteristic of men at that age. If a psychiatric workup finds nothing and the symptoms persist, hormones come onto the list.
7. Cognitive fog
Harder to measure, but consistently reported. A fog that is not relieved by a good night's sleep, not explained by workload, not relieved by caffeine. Difficulty focusing on tasks that used to be straightforward.
On its own, this is a weak signal. Combined with two or three of the above, it becomes more interesting.
What does not, on its own, indicate low testosterone
- Mild weight gain in middle age
- Feeling tired after a bad week
- One episode of erectile difficulty
- Hair loss (androgenic alopecia is caused by high DHT sensitivity, not low T)
- "Not being as motivated as I was at 25"
- Mild mood fluctuations
- Slower gym progress than a decade ago
These are normal aspects of aging and stress. They do not, individually, justify a testosterone panel.
What to actually ask for
If the symptom profile warrants testing, here is the correct panel:
- Total testosterone - drawn between 7am and 11am, fasted
- SHBG (sex hormone binding globulin) - to calculate free T
- LH and FSH - to distinguish primary from secondary hypogonadism
- Prolactin - elevated prolactin suppresses testosterone
- TSH and free T4 - thyroid dysfunction mimics hypogonadism
- Full blood count - baseline for monitoring if treatment starts
A single reading does not diagnose hypogonadism. Repeat testing is essential. The body's testosterone fluctuates significantly day-to-day and within a single day.
One last thing
Symptoms matter. A man with total testosterone of 8 nmol/L and zero symptoms is not, in clinical terms, hypogonadal in a way that warrants treatment. A man with 11 nmol/L and every symptom above is closer to warranting it - and a proper clinician will weigh both.
Self-diagnosis via symptom list is not diagnosis. Use the list as a prompt to see a proper clinician. Not as a reason to buy anything.
ELMAUCHO is a journalistic publication. Nothing here is medical advice. If the symptoms above describe you, speak to your GP.