Key Takeaways
- Low testosterone (male hypogonadism) occurs when the body doesn’t produce enough of the male sex hormone.
- Causes range from aging and medical conditions to pituitary gland issues and lifestyle factors.
- Symptoms of low testosterone include fatigue, low libido, mood changes, and reduced muscle mass.
- A proper diagnosis requires a blood test.
- Testosterone replacement therapy can safely restore hormone levels when medically appropriate.
- Treating low testosterone can improve energy, mental clarity, and relationship health.
Low energy, changes in sex drive, difficulty maintaining muscle, and a general sense that your body isn’t responding the way it used to: these are concerns many men notice over time, but they’re often misunderstood or brushed off as part of aging.
In reality, these shifts are frequently tied to low testosterone, a medical condition that can affect how you feel, perform, and function day to day. Testosterone is the primary male sex hormone, playing a central role in muscle development, metabolism, mood, and sperm production.
This is more common than you might think. The Endocrine Society reports that approximately 35% of men older than 45 years of age have low testosterone levels.
When your testosterone levels drop below what your body needs, the impact can extend well beyond the physical.
At our internal medical office in Naples, Florida, we take a clinical, data-driven approach to identifying the cause of low testosterone and developing treatment plans for men that are grounded in real biology.
What Causes Low Testosterone in Men?
Understanding what causes low testosterone in men starts with how testosterone is produced.
Your brain, specifically the hypothalamus and pituitary gland, signals your testes to produce testosterone through hormones like luteinizing hormone. When that system breaks down at any point, testosterone production can decline.
There are two primary categories of male hypogonadism:
(1) Primary Hypogonadism (Testicular Origin)
This occurs when the testes cannot produce adequate testosterone, even when properly signaled.
Common causes include:
- Genetic conditions
- Injury or trauma to the testes
- Chemotherapy or radiation
- Chronic illness
(2) Secondary Hypogonadism (Brain/Pituitary Origin)
This involves dysfunction in the hypothalamus or pituitary gland, meaning the signal to produce testosterone is impaired.
Potential causes include:
- Pituitary disorders
- Certain medications
- Obesity
- Chronic stress
In some cases, men may experience a combination of both primary and secondary causes, which is referred to as mixed hypogonadism. This is especially common as men get older or when multiple health factors are involved. Identifying where the breakdown is occurring (whether in the testes, the pituitary gland, or both) is what allows for a more precise diagnosis and treatment plan.
That’s why a thorough evaluation, including lab work and clinical assessment, is necessary before considering any form of testosterone therapy or hormone replacement therapy.
Medical and Lifestyle Factors That Lower Testosterone
Low testosterone isn’t always caused by a single issue. In many cases, it’s a combination of factors that gradually impact hormone production over time.
Aging
Testosterone levels naturally decline with age, typically decreasing by about 1% per year after age 30. However, not every man develops clinically significant testosterone deficiency, which is why symptoms and lab results both matter in diagnosis.
Obesity and Metabolic Health
Excess body fat can interfere with hormone signaling and reduce testosterone production. In fact, research shows a clear relationship between obesity and declining testosterone levels in men.
A recent clinical review found that higher body fat and increased BMI are consistently associated with lower circulating testosterone, partly because fat tissue increases aromatase activity: an enzyme that converts testosterone into estrogen. The study also found that reducing body fat through weight loss can significantly improve testosterone levels and overall hormonal balance.
Obstructive Sleep Apnea
Men with obstructive sleep apnea often experience lower testosterone levels due to disrupted sleep cycles. Studies have found that untreated sleep apnea is associated with reduced nighttime testosterone production, which is when levels typically peak.
Chronic Conditions
Conditions like diabetes and high blood pressure can negatively impact hormone balance. According to the American Diabetes Association, up to 1 in 3 men with type 2 diabetes have low testosterone, often linked to insulin resistance and metabolic dysfunction.
Medications
Certain medications, especially opioids and long-term corticosteroids, can suppress testosterone production. These drugs can interfere with signals from the hypothalamus and pituitary gland, reducing the release of hormones needed to stimulate testosterone production in the testes.
Over time, this disruption can contribute to male hypogonadism, particularly in men using these medications on a long-term or high-dose basis.
Symptoms of Low Testosterone
The symptoms of low testosterone can vary, but most men notice a combination of physical, mental, and sexual changes:
- Reduced sex drive
- Erectile dysfunction
- Fatigue or low energy
- Loss of muscle mass
- Increased body fat
- Mood changes or irritability
- Difficulty focusing
- Decreased sperm production
In some cases, low testosterone may also affect bone density and lead to changes in red blood cells, contributing to fatigue.
How Low Testosterone Is Diagnosed
Diagnosing low testosterone starts with a detailed evaluation, not assumptions based on symptoms alone. Because many signs of low testosterone overlap with other health conditions, an accurate diagnosis requires both clinical insight and objective data.
Step 1: Clinical Assessment
We begin by reviewing your symptoms, medical history, and overall health. This includes discussing changes in energy, libido, mood, body composition, and performance, as well as identifying any underlying conditions or medications that may be affecting your testosterone levels.
Step 2: Blood Testing
A blood test measures your testosterone levels, typically in the morning when levels are highest.
We also evaluate:
- Free and total testosterone
- Luteinizing hormone
- Other markers that help determine whether the issue originates in the testes or the pituitary gland
What Are Normal Testosterone Levels?
A verdict of “testosterone levels normal” can vary depending on age and lab standards. Diagnosis is based on both lab values and symptoms, not numbers alone.
Treatment Options for Low Testosterone
When low testosterone is confirmed, treatment focuses on restoring balance safely and effectively.
Testosterone Replacement Therapy (TRT)
Testosterone replacement therapy is the most common and clinically proven treatment for men with confirmed male hypogonadism. TRT works by supplementing your body’s testosterone to bring levels back into a healthy range.
Common Forms of Testosterone Therapy:
- Injections
- Topical gels or creams
- Pellets
- Oral testosterone (in select cases)
Each option has different benefits depending on your lifestyle, preferences, and medical history.
What to Expect From Testosterone Therapy
When testosterone therapy is prescribed based on a confirmed diagnosis and managed appropriately, it can lead to measurable improvements in how your body functions and how you feel day to day. The goal is not to push levels beyond normal ranges, but to restore your testosterone levels to a range that supports consistent energy, strength, and overall health.
With properly managed testosterone therapy, many men report:
- Improved energy levels
- Increased muscle mass
- Better mood and mental clarity
- Stronger libido
- Improved overall quality of life
Most men begin to notice gradual improvements within a few weeks, with more significant changes developing over several months as hormone levels stabilize.
At the same time, results can vary depending on your baseline health, the underlying cause of low testosterone, and how your body responds to treatment.
That’s why ongoing monitoring is part of every responsible plan. Regular follow-up appointments and lab work help track testosterone levels, evaluate red blood cells, and assess overall health markers to keep treatment both safe and effective.
Safety Considerations
Taking hormone replacement therapy requires careful oversight to protect your health and ensure treatment is appropriate over time.
While testosterone replacement therapy can be highly beneficial for men with confirmed low testosterone, it is not a set-it-and-forget-it solution. Ongoing monitoring allows us to track how your body is responding, adjust dosing when needed, and identify any changes early.
Monitoring Matters
We track:
- Testosterone levels
- Red blood cells (to avoid thickened blood)
- PSA levels related to prostate cancer risk
- Overall health markers
Prostate Health
Men with active prostate cancer are typically not candidates for testosterone replacement therapy. Screening is part of every responsible treatment plan.
Is Testosterone Therapy Right for You?
Not every man with symptoms needs testosterone therapy, and not every low lab value requires treatment.
The right approach depends on:
- Your symptoms
- Your lab results
- Your long-term health goals
At Dr. Diane Brzezinski’s office, every patient is evaluated by a board-certified physician with a focus on identifying the underlying cause of low testosterone rather than simply treating symptoms. Dr. Brzezinski takes a medical, evidence-based approach to hormone care, combining detailed lab analysis, clinical assessment, and ongoing monitoring to guide each treatment plan.
Care doesn’t stop once testosterone replacement therapy begins. Patients are followed closely with routine lab work and check-ins to track testosterone levels, assess red blood cells, and monitor overall health markers, including prostate health. Adjustments are made as needed to keep treatment aligned with your physiology and long-term goals.
This level of oversight is what separates medically guided testosterone therapy from generalized or one-size-fits-all approaches. We’re proud to provide a higher standard of care for men looking to restore balance, performance, and overall well-being.
Take the First Step Toward Feeling Like Yourself Again
If you’ve been dealing with fatigue, low motivation, or changes in performance, it’s worth taking a closer look at your hormone health.
A simple blood test can provide clarity. If treatment is appropriate, we’ll guide you through every step of the process.
Schedule your consultation with Dr. Brezezinski today.
FAQs
1) What causes low testosterone in men most commonly?
The most common causes include aging, obesity, chronic health conditions, and dysfunction of the pituitary gland or testes.
2) How do I know if I have low testosterone?
The best way to know is through a blood test combined with a review of symptoms like fatigue, low libido, and muscle loss.
3) What is male hypogonadism?
Male hypogonadism is a medical condition where the body does not produce enough testosterone due to issues in the testes or hormone signaling from the brain.
4) Is testosterone replacement therapy safe?
When prescribed and monitored by a physician, testosterone replacement therapy is generally safe. Regular monitoring of testosterone levels, red blood cells, and prostate health is required.
5) Can testosterone therapy affect fertility?
Yes. Some forms of testosterone therapy can reduce sperm production, so this should be discussed if fertility is a concern.
6) Does testosterone therapy increase prostate cancer risk?
Current evidence does not show that TRT causes prostate cancer, but men are routinely screened before and during treatment.
