Before we begin: A testosterone level is only one piece of your health story. Persistent symptoms deserve real medical evaluation, not a guess or a supplement ad.
Sometimes it is the testicles
Primary hypogonadism means the testicles are not producing enough testosterone even when the pituitary is trying to stimulate them. Causes can include genetic conditions such as Klinefelter syndrome, testicular injury or infection, chemotherapy, radiation, and some other illnesses. LH and FSH testing helps identify this pattern.
Sometimes it is the control center
Secondary hypogonadism means the hypothalamus or pituitary is not sending enough of the right signals. Pituitary problems, high prolactin, certain medications, and other medical disorders can contribute. Some men need specific testing or pituitary imaging—not every man with a low reading needs an MRI.
Weight and metabolic health
Obesity and insulin resistance can be linked to lower testosterone measurements. Sometimes the relationship is reversible with weight loss and improved health. Treating diabetes, supporting weight management, and improving physical activity may help, but outcomes vary. The aim is better health, not a promise that a certain diet will double your T.
Sleep: your forgotten hormone appointment
Short sleep and conditions such as obstructive sleep apnea may affect testosterone or contribute to similar symptoms. Loud snoring, daytime sleepiness, witnessed breathing pauses, and high blood pressure should prompt consideration of sleep apnea evaluation. Treating sleep disorders benefits health even if testosterone levels do not change dramatically.
Medications and substances
Long-term opioid use, glucocorticoids, anabolic steroid use or withdrawal, and certain other medications can suppress the testosterone system. Heavy alcohol use and severe illness may contribute. Never stop a prescribed medication on your own; a clinician can review options and determine what is reversible.
Age is part of the picture, not the diagnosis
Average testosterone levels can decline with age, but aging alone does not establish hypogonadism or mean that every older man needs treatment. Clinicians should base decisions on persistent symptoms, reliable repeat lab testing, other causes, medical risks, and individual goals.
The takeaway
You may have low testosterone because of a medical condition that deserves treatment, or because another problem is temporarily affecting the hormone system. Understanding which comes first can change everything.
Next: Which Testosterone Tests Do You Actually Need?
Total T, free T, LH, FSH, SHBG, prolactin: a plain-English guide to the alphabet soup.
Read next guide →Medical sources & further reading
Guideline-based educational background; recommendations may vary by patient and country. See original sources for detailed clinical criteria.
- American Urological Association: Testosterone Deficiency
- Endocrine Society: Testosterone Therapy Guideline
- Endocrine Society: 2026 Statement
- FDA: Testosterone Information and Updated Labels
- European Association of Urology: Male Hypogonadism
- American College of Physicians: Testosterone Treatment Guideline
This is educational content, not personal medical advice. A licensed clinician must evaluate symptoms and laboratory results, decide on treatment, and monitor risks. Do not start or stop prescription hormones without medical supervision.