Introduction
Feeling constantly tired, experiencing a reduced sex drive, or noticing changes in muscle strength can sometimes indicate an underlying health concern. While stress, poor sleep, and lifestyle habits may contribute to these symptoms, hormonal changes such as low testosterone in men can also play a role.
Testosterone is the primary male sex hormone. It is essential for male reproductive health, sperm production, muscle development, bone strength, and the regulation of sexual desire. Testosterone levels naturally change with age, but abnormally low levels accompanied by symptoms may indicate a condition known as male hypogonadism.
A testosterone blood test can help evaluate hormone levels and determine whether further medical assessment is necessary. However, symptoms alone cannot confirm low testosterone, and a single abnormal test result may not be sufficient for diagnosis.
In this blog, we explore the common symptoms of low testosterone in men, its possible causes, when to get tested, and how to prepare for a testosterone blood test.
What Is Testosterone and Why Is It Important for Men?
Testosterone is a hormone produced primarily by the testicles, with smaller amounts produced by the adrenal glands. Its production is regulated by signals from the brain, particularly the hypothalamus and pituitary gland.
Testosterone plays several important roles in men's health, including:
- Supporting sexual desire and erectile function.
- Helping maintain muscle mass and strength.
- Supporting bone density.
- Contributing to sperm production and reproductive function.
- Supporting red blood cell production.
- Influencing energy, mood, and overall well-being.
Testosterone levels vary between individuals and can fluctuate throughout the day. They are generally highest in the morning in younger adult men.
When testosterone levels are consistently low and associated with relevant symptoms, medical evaluation may be needed to identify the underlying cause.
7 Common Symptoms of Low Testosterone in Men
The symptoms of low testosterone can develop gradually and may overlap with other health conditions. Recognising persistent changes can help men seek appropriate medical advice.
1. Reduced Sex Drive
One of the common symptoms of low testosterone is a decrease in sexual desire or interest in sexual activity.
Although libido can be affected by stress, relationship concerns, medications, and other health conditions, a persistent reduction in sex drive may warrant a medical assessment.
2. Erectile Dysfunction
Some men with low testosterone experience difficulty achieving or maintaining an erection. However, erectile dysfunction has many possible causes, including diabetes, cardiovascular disease, medication effects, and psychological factors.
Testosterone testing may be considered when erectile dysfunction occurs alongside other symptoms of testosterone deficiency.
3. Persistent Fatigue and Low Energy
Feeling tired despite adequate rest can have several explanations. Low testosterone may contribute to reduced energy, decreased motivation, or a general feeling of fatigue in some men.
Other possible causes include anaemia, thyroid disorders, sleep apnoea, and nutritional deficiencies. A doctor can determine whether testosterone testing or other investigations are appropriate.
4. Loss of Muscle Mass and Strength
Testosterone supports muscle development and maintenance. When levels are abnormally low, men may notice reduced muscle mass, decreased strength, or difficulty maintaining their usual fitness levels.
These changes can also result from ageing, inadequate physical activity, insufficient protein intake, or other medical conditions.
5. Increased Body Fat
Low testosterone may be associated with changes in body composition, including increased body fat. Some men may notice an increase in abdominal fat or difficulty maintaining muscle while gaining weight.
The relationship can work both ways: obesity may also contribute to lower testosterone levels. Medical evaluation can help identify contributing factors.
6. Mood Changes and Difficulty Concentrating
Some men with testosterone deficiency report low mood, irritability, reduced motivation, or difficulty concentrating.
These symptoms are not specific to testosterone deficiency and may also be associated with stress, depression, poor sleep, or other medical conditions.
Persistent mood changes should be discussed with a qualified healthcare professional rather than automatically attributed to hormonal imbalance.
7. Reduced Facial or Body Hair and Other Physical Changes
More significant testosterone deficiency may cause reduced facial or body hair growth, breast enlargement, smaller testicular size, or a reduction in bone density.
Men with long-standing testosterone deficiency may also develop anaemia or experience fractures related to reduced bone strength.
These symptoms require medical evaluation to identify the underlying cause.
What Causes Low Testosterone in Men?
Low testosterone can result from problems affecting the testicles, the hypothalamus, or the pituitary gland. Certain health conditions and lifestyle factors may also contribute.
Common causes and contributing factors include:
- Ageing: Testosterone levels often decline gradually with age, although ageing alone does not establish a diagnosis of testosterone deficiency.
- Obesity: Excess body fat is associated with lower testosterone levels.
- Type 2 diabetes and metabolic conditions: These may be associated with reduced testosterone, particularly when other risk factors are present.
- Testicular conditions: Injury, infection, or certain medical treatments can affect testosterone production.
- Pituitary or hypothalamic disorders: These may interfere with the signals that regulate testosterone production.
- Certain medications: Opioids and some other medicines can suppress testosterone production.
- Cancer treatment: Chemotherapy or radiation involving relevant areas may affect reproductive hormone function.
- Sleep disorders and chronic illness: Conditions such as obstructive sleep apnoea and severe illness can influence hormone levels.
Poor sleep, inadequate nutrition, excessive alcohol consumption, and overtraining may also contribute to hormonal changes in some circumstances.
Identifying the cause is important because treatment depends on the underlying condition.
When Should Men Get a Testosterone Blood Test?
A testosterone blood test may be recommended when a man has persistent symptoms suggestive of testosterone deficiency.
Consider consulting a doctor if you experience:
- Persistent reduction in sexual desire.
- Erectile dysfunction alongside other possible symptoms.
- Unexplained loss of muscle mass or strength.
- Persistent fatigue with other signs of hormonal deficiency.
- Reduced facial or body hair growth.
- Infertility or concerns about sperm production.
- Unexplained anaemia or reduced bone density.
- A history of testicular injury or pituitary disease.
Having one or more of these symptoms does not necessarily mean you have low testosterone. A medical assessment helps determine whether testing is appropriate.
Routine testosterone screening is not recommended for every man without symptoms. Testing is generally guided by clinical findings and individual risk factors.
Which Blood Test Measures Testosterone Levels?
The primary investigation used to evaluate suspected testosterone deficiency is the total testosterone blood test.
1. Total Testosterone Test
This test measures the total amount of testosterone circulating in the blood, including testosterone bound to proteins and the small amount that is unbound.
Doctors generally recommend measuring testosterone in the morning, often between 7 a.m. and 10 a.m., particularly for men with conventional sleep schedules. Testing may need to be repeated on a separate morning if the first result is low.
2. Free Testosterone Test
Free testosterone refers to the fraction of testosterone that is not bound to proteins.
A free testosterone assessment may be helpful when total testosterone results are borderline or when conditions affecting sex hormone-binding globulin (SHBG) could influence interpretation.
The method used to assess free testosterone matters, so the result should be interpreted by a qualified healthcare professional.
3. LH and FSH Tests
If low testosterone is confirmed, doctors may recommend Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH) tests.
These hormones help distinguish between problems primarily affecting the testicles and problems involving the pituitary gland or hypothalamus.
4. Prolactin Test
A prolactin test may be recommended in selected cases, particularly when testosterone is low and LH levels suggest a possible pituitary-related cause.
Additional investigations depend on the individual's symptoms, medical history, and initial test results.
What Is the Normal Testosterone Level in Men?
Testosterone reference ranges vary by laboratory, testing method, age, and clinical context.
For example, a commonly cited reference range for total testosterone in healthy, non-obese men aged 19–39 is approximately 264–916 ng/dL using a standardized measurement approach. This is not a universal range for every man or every laboratory.
Some clinical guidelines use a total testosterone level below approximately 300 ng/dL as a reasonable threshold supporting the diagnosis when relevant symptoms are present. However, diagnosis requires more than comparing a result with a single number.
Doctors generally consider:
- Whether symptoms are consistent with testosterone deficiency.
- Whether the level is repeatedly low on separate morning tests.
- The laboratory's reference range and testing method.
- Whether other medical conditions or medications could affect the result.
- Whether free testosterone assessment or further hormone tests are necessary.
Important: A testosterone result should not be interpreted in isolation. A healthcare professional can explain what your individual result means.
How to Prepare for a Testosterone Blood Test
Following the correct preparation instructions can help ensure reliable results.
- Schedule the test appropriately: Morning testing is generally preferred, especially when testosterone deficiency is suspected.
- Follow fasting instructions: Some clinicians recommend testing while fasting, particularly when investigating low testosterone. Confirm this with your doctor or laboratory.
- Inform your doctor about medications: Certain medicines, supplements, and hormone treatments can affect the results. Do not stop prescribed medication without medical advice.
- Mention sleep patterns: Shift work and irregular sleep schedules may affect the appropriate timing of testing.
- Avoid testing during significant acute illness when possible: Severe illness can temporarily lower testosterone levels. Your doctor may recommend testing after recovery.
If your first result is low, your doctor may arrange a repeat test before confirming a diagnosis.
Can Low Testosterone Be Treated?
Yes. Treatment depends on the cause, severity of the deficiency, symptoms, and reproductive goals.
Possible approaches include:
1. Addressing underlying health conditions: Managing obesity, diabetes, sleep disorders, or other contributing conditions may improve overall health and, in some cases, testosterone levels.
2. Improving lifestyle habits: Regular physical activity, adequate sleep, balanced nutrition, and maintaining a healthy weight can support general metabolic and reproductive health.
3. Reviewing medications: A doctor may review medicines that could be contributing to low testosterone and consider alternatives where appropriate.
4. Testosterone replacement therapy (TRT): Testosterone treatment may be considered for men with confirmed testosterone deficiency and relevant symptoms after a medical assessment. It may be given in different formulations, depending on individual circumstances.
Testosterone replacement therapy is not suitable for everyone. It can suppress sperm production and reduce fertility, so men planning to have children should discuss this before treatment. Monitoring is also required because treatment can cause adverse effects, including an increase in red blood cell count.
Never start testosterone injections, gels, or supplements without medical supervision. Treatment should be based on an appropriate diagnosis and an individual assessment of benefits and risks.
Conclusion
Low testosterone can affect sexual health, muscle strength, energy levels, mood, and overall well-being. However, these symptoms can also occur due to several other medical conditions, making proper evaluation important.
A testosterone blood test is a useful starting point when testosterone deficiency is suspected. Doctors may recommend repeat morning testing and additional investigations, such as LH, FSH, or prolactin, to understand the underlying cause.
If you are experiencing persistent symptoms of low testosterone, consult a qualified healthcare professional to discuss whether testing is appropriate.
Take a proactive approach to men's health. Understand your symptoms, get the right tests when needed, and seek medical advice for informed decisions about your well-being.
Medical Disclaimer
Disclaimer: This article is intended for general educational and awareness purposes only. It is not a substitute for medical diagnosis, treatment or professional medical advice. Health screening recommendations vary according to age, sex, symptoms, medical history, medications, family history and individual risk factors. Please consult a qualified healthcare professional before deciding which tests or screenings are appropriate. Do not start, stop or change medication based solely on information in this article.
