What are the Causes of Low Testosterone in Young Males?

Low testosterone is often thought of as something that only affects older men, but that is not always the case. Some younger men can also experience lower than expected testosterone levels, which may affect energy, mood, sexual health and physical performance.

Because the symptoms can develop gradually and overlap with everyday stress or lifestyle changes, it is not always easy to recognise when hormones are playing a role.

Understanding what can cause low testosterone in younger men is an important first step in knowing when it may be worth checking hormone health more closely.

What testosterone does in the body

Testosterone is the main male sex hormone. It is produced primarily in the testes and is regulated by signals from the brain, specifically the hypothalamus and pituitary gland.

In younger men, testosterone plays a key role in:

• Muscle growth and strength
• Bone development and density
• Sex drive and sexual function
• Sperm production and fertility
• Energy levels and stamina
• Mood, confidence and motivation
• Mental focus and cognitive performance

Levels naturally vary between individuals, but when testosterone drops below a healthy range, it can begin to affect several areas of physical and emotional wellbeing.

Is low testosterone in young men common?

Low testosterone is less common in younger men compared with older age groups, but it is increasingly recognised in clinical practice.

In many cases, it is linked to lifestyle factors or temporary changes in health rather than a long-term condition. However, it can still have a noticeable impact on day-to-day life.

Because symptoms often overlap with stress, poor sleep or general fatigue, hormone-related changes can sometimes go unnoticed.

Causes of low testosterone in young males

There is no single cause of low testosterone. In younger men, it is usually the result of a combination of lifestyle, health and biological factors.

1. Chronic stress and cortisol levels

Stress has a direct impact on hormone balance. When the body is under ongoing stress, it produces higher levels of cortisol.

Cortisol and testosterone work in opposite ways in the body. When cortisol remains high for long periods, it can:

• Reduce signals from the brain that stimulate testosterone production
• Disrupt the hormonal feedback system
• Affect sleep, which is essential for hormone regulation

Over time, this can lead to lower testosterone levels and symptoms such as fatigue, low mood and reduced motivation.

2. Poor sleep patterns

Sleep is one of the most important factors in testosterone production. Most testosterone is released during sleep, particularly during deep sleep stages.

Young men who regularly experience poor sleep may be more likely to see changes in hormone levels.

This can include:

• Reduced total testosterone production
• Disruption of the body’s natural hormone rhythm
• Increased tiredness and reduced recovery

Even short-term sleep disruption can affect energy levels and performance, while longer-term issues may have a greater impact on hormonal balance.

3. Higher body fat levels

Body composition plays a significant role in testosterone levels. Higher levels of body fat, particularly around the abdomen, are linked with lower testosterone. This is partly due to increased activity of an enzyme called aromatase, which converts testosterone into oestrogen.

Higher body fat can also:

• Affect insulin sensitivity
• Increase inflammation in the body
• Reduce overall energy levels

These changes can contribute to a cycle where low testosterone and weight gain influence each other over time.

4. Low physical activity or overtraining

Exercise has a direct effect on hormone balance, but both too little and too much can influence testosterone levels.

• Low activity levels may reduce muscle mass and hormonal stimulation
• Excessive training without enough recovery can increase stress hormones

Strength training in particular is associated with healthy testosterone levels, especially when balanced with rest and recovery.

5. Nutritional factors

Diet plays a key role in hormone production. Certain nutrients are particularly important for testosterone, including zinc, vitamin D and healthy fats. Low intake of these nutrients may affect hormone production over time.

Diets that are very restrictive, low in calories or lacking in variety may contribute to hormonal imbalance, particularly if followed for extended periods.

6. Medical conditions

Some health conditions can affect testosterone levels in younger men. These include:

• Thyroid disorders
• Pituitary gland conditions
• Type 2 diabetes
• Testicular injury or conditions affecting the testes
• Chronic liver or kidney disease

In some cases, low testosterone may be one of several symptoms linked to an underlying condition that requires medical support.

7. Medications

Certain medications can affect testosterone levels. These may include:

• Some antidepressants
• Opioid-based pain relief
• Steroid treatments
• Medications used for long-term health conditions

If symptoms begin after starting a new medication, it may be worth discussing this with a healthcare professional.

8. Natural variation and genetics

Hormone levels can vary naturally between individuals. Some men may have lower baseline testosterone due to genetic factors.

This does not always indicate a health problem, but it can still influence how someone feels in terms of energy, strength and mood.

Signs of low testosterone in younger men

Symptoms of low testosterone can vary, but common signs include:

• Persistent fatigue
• Reduced muscle strength
• Increased body fat
• Low libido
• Erectile dysfunction
• Reduced motivation
• Mood changes or irritability
• Difficulty concentrating

These symptoms can also be linked to other factors, which is why testing is often needed to confirm whether testosterone is involved.

Why testosterone matters in younger adulthood

Testosterone plays an important role not just in physical health, but also in overall wellbeing.

In younger men, it can influence:

• Daily energy levels
• Confidence and motivation
• Mental clarity and focus
• Physical performance
• Reproductive health and fertility

When levels are outside the expected range, the effects can be noticeable across several areas of life.

When to consider a hormone test

It may be helpful to check testosterone levels if you are experiencing:

• Ongoing tiredness without clear cause
• Reduced sex drive
• Changes in mood or motivation
• Difficulty building or maintaining muscle
• Unexplained changes in body composition
• Fertility concerns

A blood test can help determine whether testosterone levels are within a healthy range and whether further investigation is needed.

Take control of your hormone health

If you are experiencing symptoms that may be linked to low testosterone, or simply want a clearer picture of your hormone health, testing can be a useful first step.

Bluecrest Wellness offers a Male Hormone Profile, designed to assess key hormones linked to energy, mood, fertility and overall wellbeing.

The test includes:

• A convenient blood test appointment
• A detailed results report
• A private GP consultation to discuss your findings

BOOK AN ADVANCED MALE HORMONE CHECK TODAY

Need help? You can reach out to our corporate team on 0808 168 9219