Low testosterone is one of the findings we pick up most often in men at a health check. It is also one of the easiest to miss, because its symptoms are so easily put down to a busy job, poor sleep or simply getting older.

What testosterone does

Testosterone is the main male sex hormone. As well as sex drive and erections, it affects energy, mood, concentration, muscle strength, body fat and bone strength. Levels fall slowly with age, but a significant drop is not an inevitable part of getting older, and it often has a cause that can be treated.

Symptoms of low testosterone

• Low sex drive, or fewer spontaneous (morning) erections
• Erectile problems
• Tiredness and lack of energy
• Low mood, irritability or poor concentration
• Loss of muscle strength, and more fat around the middle
• Poor sleep, and reduced drive or motivation

None of these symptoms is specific. Each can have other causes, from thyroid problems and low vitamin levels to depression and sleep apnoea. That is why testosterone should be measured and interpreted by a doctor alongside your history, rather than guessed at.

Why the timing of the blood test matters

Testosterone levels follow a daily rhythm. They are highest in the early morning and can fall considerably by the afternoon, particularly in younger men. A sample taken late in the day can make a normal level look low.

For that reason, UK guidance recommends measuring testosterone in the morning, ideally before 11am. A single low result should be repeated on another morning before any diagnosis is made. We also measure SHBG (sex hormone binding globulin), the protein that carries testosterone in the blood, because it affects how much testosterone is actually available to your body.

If you are booking a health check with us, please choose a morning appointment where you can.

Common causes of low testosterone

Low testosterone is often a sign of something else going on, and many of the causes can be improved:

• Carrying extra weight, especially around the waist
• Type 2 diabetes or prediabetes
• Poor sleep, including obstructive sleep apnoea
• Heavy drinking
• Recent illness, significant stress or very intense training
• Some medicines, including long-term opioid painkillers and steroids
• Less commonly, problems with the testes or the pituitary gland

What happens if your level is low

The first step is to confirm the result with a repeat morning test and look for a cause. That may mean further blood tests, including other hormones that control testosterone production. Treating the cause, such as losing weight, improving sleep or cutting down on alcohol, can raise testosterone on its own.

Where testosterone is confirmed to be low and symptoms are affecting your life, treatment may be appropriate. This is a decision to make with a doctor after a full assessment, as treatment is long-term and needs regular monitoring.

Testing at Zenvité

Low testosterone was one of the main modifiable findings in our audit of health checks, which is why testosterone and SHBG are included in both our Core and Advanced Health Checks. Every result is reviewed by a doctor and explained in your personal results report, with a clear plan if anything needs repeating or following up.