A man in his late 40s sits down in my office and says, “Doctor, I think my testosterone is low.”

Sometimes he is already holding lab results. Sometimes he is coming from a gym forum, a friend’s recommendation, or a late-night Google search. But almost always, the story sounds familiar: lower sex drive, fewer morning erections, weaker erections, fatigue, brain fog, mood changes, and that stubborn belly fat that seems to arrive overnight.

Here is the part I tell patients early, because it changes everything:

Male hypogonadism isn’t just a low number. It is a medical diagnosis. It means symptoms that fit plus consistently low morning testosterone, and it can affect more than sex drive alone.

Why this matters (and why we should slow down)

Testosterone influences more than many people realize: sexual function, energy, mood, sleep, muscle and fat distribution, bone health, and sometimes urinary symptoms. That is why the safest approach is not to “treat a number,” but to understand the whole picture.

Who is more likely to have low testosterone

Testosterone can decline a little with age, but I see clinically meaningful low testosterone more often in men with obesity and chronic health problems, especially type 2 diabetes, metabolic syndrome, and cardiovascular disease.

In many of these cases, it is functional hypogonadism. In simple terms, the body’s testosterone system is being “turned down” by health factors (most commonly excess weight and metabolic problems, and sometimes medications), rather than the testes being permanently “broken.” Because of that, levels can sometimes improve when the underlying health issues are treated.

The three main types:

• Primary: The testes cannot make enough testosterone.
• Secondary: The brain/pituitary isn’t sending the right signals.
• Functional: The system is suppressed by health factors (often at least partly reversible).

Total testosterone vs. free testosterone: the simple explanation

Most testosterone in the bloodstream rides on “carrier” proteins, especially a tighter-binding carrier called sex hormone-binding globulin (SHBG) and also albumin. Only a small fraction circulates as “free” testosterone, which is the portion most readily available to tissues.

That is why two men can have similar total testosterone levels but feel very different, especially if one has higher SHBG (less free testosterone) or lower SHBG (more free testosterone). This is also why guidelines recommend in some cases checking or correcting for SHBG and estimating free testosterone when SHBG is altered or when total testosterone is borderline.

My “low T” checklist: a safe, practical approach

This is the structure I use to keep the evaluation accurate and safe, and yes, the key steps get revisited again during follow-up.

1. Start with symptoms and goals

We talk through sex drive, erections, energy, mood, sleep, and exercise tolerance. I also review medications and ask about fertility plans, because testosterone therapy can suppress sperm production and isn’t appropriate if you are actively trying to conceive.

2. Confirm it with properly done labs (not just once)

Testosterone varies day to day, so one test isn’t enough. Guidelines recommend a reliable morning (07:00 to 11:00), fasting total testosterone, and repeating it on at least two separate mornings, especially when it is low or borderline, before starting treatment.

3. Look for the cause (and rule out “organic” problems)

Low testosterone can come from the testes, from pituitary/hypothalamus signaling, or be “switched down” by health factors. Blood tests like LH/FSH (and sometimes prolactin) help clarify the pattern, and pituitary imaging is considered when results or symptoms point that way.

Where “functional hypogonadism” fits: When symptoms are present and testosterone is repeatedly low, but no permanent structural cause is found, guidelines describe functional hypogonadism as a diagnosis of exclusion, often linked to comorbidities and/or medications. For overweight or obese men, the first-line approach is lifestyle change and weight reduction, plus, when possible, adjusting medications that may interfere with testosterone production before jumping straight to testosterone therapy.

4. Check baseline safety before treatment

Before prescribing testosterone, I check a blood count (because testosterone can raise red blood cell levels), metabolic risk markers, and I make a prostate safety plan. Some guidelines specifically recommend PSA and a prostate exam (DRE) in men over 40 before starting testosterone to help rule out an unrecognized prostate cancer.

5. Decide together (including who should not take TRT)

Testosterone therapy is not for everyone. Guidelines list untreated prostate cancer or breast cancer and severe heart failure as contraindications, and consider severe urinary symptoms or a high hematocrit (about greater than 48 to 50 percent) as relative reasons to avoid or delay therapy.

If treatment is appropriate, transdermal testosterone (gel or patch) is often preferred when starting. And if fertility is a goal (especially in secondary hypogonadism), gonadotropin therapy may be the better option instead of testosterone.

6. Follow-up is part of the prescription

After starting (or choosing not to start) therapy, we reassess symptoms and repeat key labs to confirm levels are appropriate and to watch safety markers. That is how testosterone care stays effective and safe.

If you are exploring telehealth, it helps to know what a safe online process should include (blood testing, clinician review, and monitoring). This external patient guide walks through it.

“What number counts as low?”

Patients understandably want one cutoff. In real life, diagnosis depends on symptoms plus confirmed morning labs. A commonly used practical threshold for late-onset hypogonadism, when symptoms are present, is around 12 nmol/L, with free testosterone considered when needed.

If we treat: what testosterone therapy is (and what it isn’t)

If a man truly has hypogonadism, testosterone therapy can help, especially for sexual symptoms and sometimes energy and body composition. But I frame it clearly:

• It is replacement, not “anti-aging medicine.”
• It doesn’t replace sleep, exercise, weight management, or diabetes control.
• It requires follow-up, because monitoring is part of safe therapy.

Testosterone comes in several forms (gels, skin preparations, injections, and other options). The “best” form is usually the one that fits your life and can be used consistently, with proper monitoring.

The one sentence I want every patient to remember

Do not start testosterone on your own or based on one lab result. Always discuss symptoms and results with a qualified clinician, ideally your urologist, primary care physician, or an endocrinologist, so the diagnosis is confirmed and the cause is not missed.

And if you are already on testosterone, don’t hesitate to ask: What are we monitoring, how often, and what are we aiming for? A good plan should be clear.

Because the goal is simple: Help you feel better, safely, with the right diagnosis and the right follow-up.

Martina Ambardjieva is a dedicated urologist and medical educator with extensive experience in both clinical practice and academic instruction. She earned her MD from the University “Sv. Kiril i Metódij” in Skopje and is a PhD candidate in urological oncology, with a focus on bladder carcinoma. Her scholarly work includes numerous publications in oncologic urology, urinary calculosis, and men’s health.

Dr. Ambardjieva currently serves as a urologist at the PHI University Surgical Clinic “Naum Ohridski” and completed her residency training at the University Urology Clinic in Skopje. Earlier in her career, she practiced as a general medical doctor at Sante Plus General Hospital and completed a medical internship at the University of Ljubljana.

In addition to her clinical responsibilities, Dr. Ambardjieva is a teaching assistant at the Medical Faculty in Skopje. She works additionally as a collaborator for Dr. Telx. She has held leadership positions in the European Medical Students’ Association and actively participates in international medical education and policy. She has attended numerous congresses and workshops in France, Italy, Canada, and Turkey, and serves as a delegate for the European Association of Urology (EAU), contributing to cross-border initiatives in urology. Certified in laparoscopic surgery, she continues to integrate patient care, research, and education in her professional work.