Low testosterone, also called testosterone deficiency or hypogonadism, causes tiredness, low mood, reduced sex drive, weaker erections and loss of muscle. It is diagnosed with two morning blood tests and can be treated, but treatment needs to be weighed carefully, especially for men who may still want children.
Tiredness that sleep does not fix, a sex drive that has quietly faded, a shorter temper, less strength in the gym: men often put these down to age or work. Sometimes that is right. Sometimes the cause is a low testosterone level, which is measurable, and treatable. Mr Vinod Nargund assesses men with these symptoms, finds out whether testosterone is actually the problem, and advises honestly on what to do about it.
What are the symptoms of low testosterone?
Low testosterone rarely announces itself with one symptom. It tends to show as a cluster:
- Persistent tiredness and low energy.
- Reduced sex drive, and erections that are weaker or less frequent, including fewer morning erections.
- Low mood, irritability or difficulty concentrating.
- Loss of muscle and strength, and an increase in body fat, particularly around the middle.
- Reduced body hair, or breast tissue developing.
- Hot flushes or sweats.
Many of these overlap with depression, thyroid problems, sleep apnoea, diabetes and simple overwork, which is why the diagnosis has to be made properly rather than assumed.
How is low testosterone diagnosed?
Testosterone is highest in the morning and varies from day to day, so a diagnosis needs at least two blood tests taken before 11am on separate days, alongside other hormone tests that show where the problem lies. Mr Nargund will also look for the causes and the conditions that travel with low testosterone, including obesity, diabetes and sleep apnoea, and examine the testicles, which is where testosterone is made.
What are the treatment options?
- Treating the underlying cause. Weight loss, better sleep, treating sleep apnoea and cutting alcohol raise testosterone in many men without any medication.
- Testosterone replacement, as a gel or an injection, for men whose level is genuinely low and whose symptoms match. It can make a substantial difference to energy, mood and sexual function.
- Alternatives for men who want children. Testosterone replacement switches off the body’s own production and reduces sperm count, sometimes to zero. If you may want a family, Mr Nargund will discuss other approaches that raise testosterone without harming fertility.
Testosterone treatment needs monitoring of blood counts, PSA and the prostate, and Mr Nargund will explain those checks before you start.
When should you see a specialist?
If you have had several of the symptoms above for more than a few months, or if a GP blood test has come back low or borderline and you want a specialist view, a consultation is the right next step. Because Mr Nargund is a urologist as well as an andrologist, the same appointment covers the prostate and erectile assessment that go with this.
Sources
British Society for Sexual Medicine guidelines on testosterone deficiency, the European Association of Urology guidelines on male hypogonadism, and NHS patient information.
Reviewed by Mr Vinod Nargund, MBBS, PhD, FRCS(Urol), FEBU. Last updated 12 September 2026.