最終更新日: 2026年7月18日

As a urologist and research scholar at Baylor College of Medicine, a significant part of my day involves cutting through the noise surrounding men’s health to bring my patients the most accurate, up-to-date science. Few topics generate as much confusion—and aggressive marketing—as “Low T,” or male hypogonadism.

Recently, The Lancet Diabetes & Endocrinology published a massive 2024 review evaluating the pathogenesis, diagnosis, and management of male hypogonadism. This paper evaluated the latest clinical trials, including the landmark TRAVERSE study, fundamentally updating how we understand and treat this condition.

If you are a man over 40 wondering about your testosterone levels, here is exactly what you need to know based on the latest medical evidence.

Low Testosterone in 2024 — 6 evidence-based facts every man over 40 should know about hypogonadism, the TRAVERSE trial, and treatment safety, by Dr. Soarawee at Bangkok Hospital
Low Testosterone in 2024: 6 Things You Need to Know — a quick visual summary of the latest evidence.

The Two Faces of Low Testosterone: Organic vs. Functional

In the medical world, we do not view all testosterone deficiencies the same way. We divide male hypogonadism into two distinct categories:

  1. Organic (Classical) Hypogonadism: This occurs when there is an intrinsic, usually irreversible pathology in the hypothalamic-pituitary-testicular (HPT) axis. Conditions like Klinefelter’s syndrome or prior testicular treatments fall into this category. The treatment here is straightforward: testosterone replacement therapy.
  2. Functional (Late-Onset) Hypogonadism: This is the form driving the global surge in testosterone prescriptions. It occurs when your testosterone levels are suppressed by external factors—primarily obesity, type 2 diabetes, and the accumulation of age-related comorbidities—without any permanent structural damage to your reproductive axis

The most crucial difference? Functional hypogonadism is frequently reversible when the underlying external factors, like excess weight, are corrected.

What Are the Real Symptoms?

Many men come to the clinic blaming general fatigue or a bad mood on Low T. While those can be factors, the 2024 data makes it clear: sexual symptoms are the strongest, most accurate indicators of true testosterone deficiency.

Older man feeling fatigued and low energy — common symptom of low testosterone (hypogonadism) in men over 40
Persistent fatigue and low energy in men over 40 may be linked to declining testosterone levels.

How to Get Tested the Right Way

One of the most common mistakes I see is improper hormone testing. If we are going to evaluate your total testosterone, it must be done with precision.

脳の霧と抑うつ気分を伴うアジア人男性 — 男性における低テストステロンの二次症状
Brain fog, low motivation, and mood changes can be subtle but important signs of low testosterone.

The 2024 Playbook for Treatment & Safety

For men dealing with functional, obesity-related hypogonadism, health optimization and weight loss remain the absolute gold-standard management strategy. Losing excess weight can completely reverse the condition for many men.

However, when lifestyle changes aren’t enough, Testosterone Therapy (TTh) is a highly effective option for alleviating sexual symptoms. But is it safe? The recent TRAVERSE trial provides reassuring clarity:

結論

If you are over 40 and experiencing a decline in your sexual health accompanied by fatigue or weight gain, your body is sending you a signal. Functional hypogonadism is a complex metabolic issue, but it is highly treatable.

Distinguishing organic from functional hypogonadism is what determines whether treatment should be hormonal or metabolic. That distinction is the starting point of our low testosterone evaluation and treatment pathway.

If you are experiencing symptoms of low testosterone and would like a comprehensive evaluation, Dr. Soarawee Weerasopone offers specialist consultations in men’s health and testosterone therapy at Bangkok Hospital Headquarters. Book a Consultation.

Frequently Asked Questions About Low Testosterone

What are the most common symptoms of low testosterone?

The most specific symptoms are sexual — reduced libido, loss of morning erections, and erectile dysfunction. Secondary signs include chronic fatigue, unexplained weight gain, reduced muscle mass, and depressive moods.

What is the difference between organic and functional hypogonadism?

Organic hypogonadism involves permanent damage to the hormonal axis and usually requires testosterone replacement therapy. Functional hypogonadism is caused by external factors like obesity or diabetes and is often reversible with lifestyle changes.

How should testosterone levels be tested correctly?

Blood must be drawn in the morning between 7:00–10:00 AM while fasting. A single low reading should always be confirmed with a second test on a different day.

Is testosterone therapy safe for the heart and prostate?

According to the TRAVERSE trial, short-to-medium-term testosterone therapy does not increase the risk of major cardiac events. Rigorous studies have also found no evidence linking testosterone therapy to prostate cancer risk.

Can low testosterone be reversed without medication?

Yes — for functional hypogonadism, weight loss and treatment of underlying conditions like obesity or type 2 diabetes can fully restore testosterone levels without medication.

**免責事項:** このコンテンツは、バンコク病院本部の認定泌尿器科医であるSoarawee Weerasopone博士によって作成およびレビューされました。教育目的のみのものであり、医学的アドバイスを構成するものではありません。いかなる医療処置を開始する前にも、必ず資格のある医療専門家にご相談ください。.

医学的に記述・監修: ソアラウィー・ウィーラソポーン医師(ポム医師) — バンコク病院本社 泌尿器科専門医。 国際フェロー:ベイラー医科大学(米国)、順天堂大学(日本)、長庚紀念医院(台湾)。.

ja日本語

Dr. Soarawee Weerasopone — Urologist Bangkokをもっと見る

今すぐ購読し、続きを読んで、すべてのアーカイブにアクセスしましょう。

読み続けて