Testosterone Deficiency (Hypogonadism): Symptoms and How It Is Treated
Fatigue, low drive and difficulty concentrating are not always down to a busy schedule. The symptoms of testosterone deficiency, the correct timing for blood tests, treatment options and what men who want children need to know.
Waking up unrested, exhaustion through the day, a decline in sexual desire, loss of muscle mass despite training… Men usually attribute this picture to their workload, poor sleep or age. Yet behind these complaints there may be a measurable and treatable hormonal problem — testosterone deficiency. An assessment carried out in the right order clarifies the picture within a few weeks.
What is testosterone deficiency (hypogonadism)?
Testosterone is the principal male hormone, produced in the testes. It influences sexual desire, the physiology of erection, sperm production, muscle and bone structure, red blood cell production, mood and mental energy. Hypogonadism means a low testosterone level accompanied by matching complaints. The critical point is this: the diagnosis is made not by a laboratory result alone but by the combination of a low value with consistent symptoms. A borderline value with no symptoms is not in itself grounds for treatment.
What are the symptoms of low testosterone in men?
- A marked decline in sexual desire (libido) — usually the first sign men notice
- Less frequent morning erections and a decline in erection quality
- Fatigue lasting all day, low energy that does not lift with rest
- Loss of muscle mass and strength, increased fat around the abdomen
- Mood swings, loss of motivation, difficulty concentrating
- Disturbed sleep, hot flushes, sweating
- Reduced bone density (in long-standing deficiency)
- Reduced testicular volume, tenderness of breast tissue
None of these symptoms is specific to testosterone. Depression, thyroid disease, sleep apnoea, iron deficiency and poorly controlled diabetes can produce a very similar picture. The correct approach is therefore not to start hormone supplementation straight away but to work through the differential diagnosis.
Why does testosterone fall?
The causes fall under two main headings. In primary (testicular) causes the problem lies in the testis itself: previous mumps orchitis, testicular trauma or surgery, a history of undescended testis, chemotherapy and radiotherapy, or genetic conditions such as Klinefelter syndrome. In secondary (central) causes the pituitary-hypothalamic axis that signals the testis works insufficiently: a pituitary adenoma, high prolactin, severe chronic illness, long-term opioid or corticosteroid use.
Alongside these are the correctable causes encountered far more often today: obesity (fat tissue converts testosterone into oestrogen), untreated sleep apnoea, excess alcohol, poorly controlled type 2 diabetes, chronic stress and — increasingly, particularly in younger men — steroid or testosterone-containing products taken from outside. In a man taking external hormone through sports supplements, the body suppresses its own production; here the cause of the low value is not a disease requiring treatment but the product being used.
When and how should testosterone be tested?
Testosterone fluctuates through the day and is highest in the morning. The blood sample should therefore be taken between 07:00 and 11:00 and fasting. A sample taken in the afternoon may be low even in a healthy man and can lead to unnecessary treatment.
The standard steps of assessment are:
- Total testosterone — in the morning, repeated on at least two separate days. A diagnosis is not made on a single measurement.
- SHBG and free testosterone — calculated because the total value can be misleading in obesity, diabetes and older age.
- LH and FSH — distinguish whether the problem originates in the testis or the pituitary.
- Prolactin — if raised, pituitary imaging comes into consideration.
- Full blood count, HbA1c, thyroid function, vitamin D, lipid profile — show the accompanying picture.
- Semen analysis if children are desired — this directly changes the treatment decision.
Is low testosterone the only cause of erectile dysfunction?
No. Testosterone deficiency contributes to erectile dysfunction, but in most patients it does not explain the picture on its own. Erection is largely a matter of vascular health; arterial disease, diabetes, smoking and venous leak impair erection independently. Indeed, patients whose erectile complaints persist after testosterone has been corrected are not uncommon. Testosterone is therefore treated as one component of the erectile assessment — not as a label that explains the whole picture.
How is testosterone treatment planned?
The first step of treatment is not hormone. Correctable causes are addressed first: weight loss, treatment of sleep apnoea, diabetes control, stopping alcohol and any externally taken hormone-containing products. These steps alone can produce a marked improvement in testosterone levels, and in some patients no further treatment is needed.
Once the indication is clear, the options are:
- Testosterone replacement: given as a gel or as short- or long-acting injections. It is aimed at correcting symptoms and suppresses the body's own production.
- Treatments that stimulate the body's own production: the preferred approach in men who want children or wish to preserve fertility. It aims to support the testis's own production and protect sperm formation.
- Treatment directed at the underlying cause: where high prolactin or a pituitary problem is identified, treating that cause takes priority.
Does testosterone treatment affect fertility?
This is the most frequently overlooked and most important heading. Externally administered testosterone suppresses sperm production and, depending on the duration of use, can markedly reduce sperm count or even bring it temporarily to zero. In most men this effect reverses within months of stopping treatment; however, the timescale varies between individuals and full recovery cannot be predicted in every case.
For this reason, conventional testosterone replacement is not an appropriate starting point in a man who wants children; treatment routes that support the body's own production are evaluated instead. Discussing the fertility plan before starting treatment, and raising the option of sperm freezing where appropriate, prevents a situation that is difficult to reverse later.
Why is monitoring necessary during treatment?
A patient started on testosterone treatment is reviewed at defined intervals: hormone levels, full blood count (for thickening of the blood), PSA and prostate assessment, blood pressure and lipid profile are monitored. In situations such as a history of prostate cancer, untreated severe sleep apnoea, advanced heart failure or a high haematocrit, treatment is either unsuitable or requires close follow-up. Hormone treatment continued without monitoring may carry more risk than benefit.
In summary: testosterone deficiency is a real, measurable and manageable condition — but it is not a subject to be managed with supplements bought online or on the basis of a single blood result. Two correctly timed measurements, a comprehensive hormone panel and an assessment that includes the fertility plan place treatment on safe ground.
Assoc. Prof. Zülfü Sertkaya practises in the field of urology and andrology in Istanbul; assessments of male hormonal health are carried out with individualised planning and full confidentiality.