Tired, Moody, and Low Energy? Dr. Nathan Starke Explains Why Low Testosterone Might Be to Blame

If you’re sleeping enough, eating reasonably well, and still waking up exhausted, something deeper may be going on. Many men chalk up chronic fatigue, irritability, brain fog, or declining motivation to stress, aging, or a demanding schedule. But according to Dr. Nathan Starke, a Houston urologist with fellowship training in Men’s Health, those symptoms often point to a commonly overlooked issue: low testosterone.

Low testosterone, or hypogonadism, isn’t just about sex drive. It’s a whole-body condition that can quietly erode a man’s physical, emotional, and mental well-being, often for years before it’s properly identified.

Testosterone: More Than a Sex Hormone

Testosterone tends to get reduced to a performance metric or a punchline , but biologically, it plays a much broader role. Adequate testosterone levels help regulate energy, mood, muscle mass, bone density, metabolism, and cognitive clarity.

The problem is that changes men may experience in these areas happen gradually. Unlike an injury or an acute illness, testosterone decline and, ultimately, deficiency sneaks up over time, making it easy to dismiss symptoms as normal aging or burnout.

The Symptoms Men Ignore First

Men with low testosterone often don’t walk into a doctor’s office asking about hormones. Instead, they describe vague, frustrating changes they can’t quite explain:

• Persistent fatigue despite adequate sleep

• Low mood, irritability, or increased anxiety

• Difficulty concentrating or “brain fog”

• Loss of motivation or drive

• Decreased muscle mass and increased body fat

• Reduced libido or weaker erections

Because the symptoms overlap with depression, stress, or poor lifestyle habits, many men are treated for everything except the underlying hormonal issue.

Why Testosterone Gets Missed

Part of the problem is how testosterone is evaluated. Traditional screening often relies on a single lab reading of total testosterone and a rigid cutoff to determine whether a man is considered “normal” or “low.”

Dr. Starke has long challenged that approach. Testosterone levels fluctuate throughout the day, and total testosterone doesn’t always reflect how much hormone is actually available for the body to use.

“If the cutoff is 300, a level of 299 is considered low and 301 is considered normal, even though those patients can feel exactly the same,” he explains, underscoring his academic research that suggests evaluating other hormones, including free testosterone, and symptoms together provides a far more accurate picture.

Low Testosterone Isn’t Just About Aging

While testosterone levels do decline with age in healthy men, Dr. Starke emphasizes that age alone shouldn’t be used to dismiss symptoms. Younger men in their 30s and 40s increasingly present with low testosterone, often tied to obesity, poor sleep, stress, metabolic disease, or underlying health conditions.

In fact, low testosterone can be both a cause and a consequence of poor health. Men with untreated sleep apnea, diabetes, or cardiovascular disease frequently have suppressed testosterone levels, and addressing hormones can sometimes be the entry point to diagnosing more serious problems.

Treatment Isn’t One-Size-Fits-All

Testosterone therapy isn’t about turning men into something they’re not. At its best, it’s about restoring balance and helping patients feel like themselves again.

For some men, treatment involves lifestyle changes.

“When men lose weight or get other chronic health issues fixed, every single aspect of their health gets better,” Dr. Starke explains. “We see improvements across the board—energy, sexual function, fertility, and overall well-being.

For others, medically supervised testosterone replacement therapy (TRT) may be appropriate.

The key, according to Dr. Starke, is individualized care. Good testosterone management isn’t about chasing numbers. It’s about matching symptoms, labs, and long-term health goals.

Reducing Stigma & Opening the Door for Long-Term Care

Despite how common testosterone deficiency is, many men delay evaluation for years. Some assume nothing can be done. Others are embarrassed to talk about symptoms that feel personal or unmanly. As testosterone treatment has begun to gain mainstream visibility, Dr. Nathan Starke has found that it has added a new, common entry point for men to seek medical care.

“Testosterone issues and treatment helped bring in patients initially patients, but also made the Men’s Health Center a front door for men of all ages to finally get themselves to the doctor.”

Feeling “Off” Is a Medical Signal, Not a Personal Failing

If you’re constantly tired, unusually moody, or feeling like your energy and drive have quietly disappeared, it may not be “just stress” or “getting older.” Low testosterone is common, treatable, and often missed.

Feeling exhausted doesn’t have to be your new normal. Sometimes, the first step toward feeling better is simply asking the right question and getting your hormones checked.