Testosterone and male hormone balance
Testosterone is an important hormone in men that affects energy levels, muscle mass, bone strength, mood, libido and sexual function. Testosterone levels naturally change with age and health, and low levels are not always the cause of symptoms.
This page explains how GPs assess testosterone concerns, when blood tests are appropriate, how results are interpreted, and when treatment may be considered.
These articles are intended as educational sources, not diagnostic nor taking place of a proper medical assessment. If you need help, please book an appointment with one of our GP’s.
What testosterone does in the body
Testosterone is produced mainly in the testes and plays a role in:
- Sexual development and function
- Libido and erectile function
- Muscle mass and strength
- Bone density
- Red blood cell production
- Mood and motivation
Testosterone levels vary throughout the day and are influenced by sleep, stress, illness, weight and medications.
Common symptoms linked to low testosterone
Symptoms attributed to low testosterone are often non-specific and overlap with many other conditions.
They may include:
- Reduced libido
- Erectile difficulties
- Fatigue or low energy
- Reduced muscle mass or strength
- Low mood or reduced motivation
- Increased body fat
- Reduced exercise tolerance
Symptoms alone are not sufficient to diagnose testosterone deficiency.
How GPs assess testosterone concerns
Assessment usually includes:
- A detailed symptom history
- Review of sleep, stress, weight and lifestyle
- Review of medications and medical conditions
- Consideration of mental health and cardiovascular risk
Blood tests are used and interpreted in clinical context.
Testosterone blood tests explained
Total testosterone
This is usually the first test checked and should be taken:
- In the morning
- On at least two separate occasions if low
Free testosterone or calculated free testosterone
These may be helpful in selected cases, particularly when sex hormone binding globulin (SHBG) is abnormal.
Additional tests
Depending on results, a GP may consider:
- LH and FSH
- Prolactin
- Thyroid function tests
- Blood count or metabolic tests
Learn more about Testosterone blood testing here.
Causes of low testosterone
Low testosterone may be related to:
- Ageing
- Obesity
- Poor sleep
- Chronic illness
- Certain medications
- Excess alcohol use
- Pituitary or testicular conditions
In many cases, testosterone levels improve with management of underlying factors.
Why symptoms do not always mean low testosterone
Many symptoms attributed to testosterone deficiency are more commonly caused by:
- Stress and burnout
- Depression or anxiety
- Sleep disorders
- Cardiovascular disease
- Metabolic health issues
A normal testosterone level usually means symptoms are unlikely to be driven by testosterone alone.
When testosterone treatment is considered
Testosterone replacement therapy is usually considered only when:
- Testosterone levels are consistently low
- Symptoms are significant
- Other causes have been excluded
- Risks and benefits have been discussed
Treatment decisions are individualised and often involve specialist input.
Important considerations before treatment
Testosterone therapy may:
- Suppress natural testosterone production
- Affect fertility
- Increase red blood cell count
- Require long-term monitoring
It is not recommended for men with normal testosterone levels.
Monitoring and follow-up
If testosterone treatment is started, follow-up may include:
- Repeat hormone testing
- Monitoring symptoms and side effects
- Blood count and PSA monitoring where appropriate
Many men are managed without medication through lifestyle and medical optimisation.
When to seek GP review
Consider GP review if:
- You have persistent symptoms affecting quality of life
- You have low testosterone blood test results
- You are considering or already using testosterone therapy
- You want help interpreting hormone results
Further Reading and Hub Links
Visit our Hormone Health hub or browse more health topics in the AccessGP Knowledge Base.
If you have concerns about testosterone levels or symptoms, a GP can assess whether testing or further review is appropriate.
Last reviewed by Dr Zamiel Hussain, GMC registered GP
Updated: 31 December 2025