Examqo › Examqo library › Urology › Andrology and penile disorders · IMLE
Male hypogonadism and testosterone therapy
A diagnosis of testosterone deficiency requires both symptoms and a low level on two separate morning tests (by AUA below 300 ng per dL); LH separates a testicular cause (high LH) from a central cause (low or normal LH), and testosterone is forbidden for a man who wants children.
Why it matters in the exam
The exam shows a man with low libido, fatigue and erectile dysfunction, and the questions deal with how to diagnose, the next tests, the contraindications and monitoring. The test is taken in the morning (before 10:00) and fasting, and repeated. When SHBG is abnormal, free testosterone is calculated. SHBG rises with older age, hyperthyroidism, cirrhosis, oestrogens, HIV and anticonvulsants; it falls with obesity, hypothyroidism, nephrotic syndrome, insulin resistance and steroids.
Primary hypogonadism (testicular, high LH and FSH): Klinefelter syndrome, orchitis (mumps), chemotherapy and radiotherapy, trauma and undescended testis. Secondary hypogonadism (central, low or normal LH): pituitary tumour, hyperprolactinaemia, opioids, obesity, chronic illness and Kallmann syndrome. When LH is low, prolactin is checked, and if prolactin is high or testosterone very low (below 150 ng per dL) — pituitary MRI. Weight loss improves the level in an obese man. In a young man with very low testosterone and small testes, Klinefelter syndrome should be considered first, and in a man on long-term opioids — central suppression that may improve with dose reduction.
Contraindications and considerations for testosterone therapy: wish for children soon (testosterone suppresses sperm production — in that case clomiphene or hCG is used), breast cancer, haematocrit above 54 percent, myocardial infarction or stroke in recent months, severe untreated sleep apnoea and severe LUTS. Monitoring: testosterone and haematocrit after 3 to 6 months and then yearly, and PSA in a man over 40. If the haematocrit rises above 54 percent — stop or reduce the dose, and sometimes perform venesection.
Key points
- Diagnosis: symptoms and two low morning tests.
- AUA: below 300 ng per dL.
- LH separates primary from secondary.
- Testosterone suppresses sperm production.
- Monitor haematocrit; above 54 percent — stop.
Summary table
| Type | LH and FSH | Examples | Further evaluation |
|---|---|---|---|
| Primary (testicular) | High | Klinefelter, mumps, chemotherapy | Karyotype |
| Secondary (central) | Low or normal | Pituitary tumour, opioids, obesity | Prolactin, MRI if needed |
| High SHBG | — | Age, hyperthyroidism, cirrhosis, HIV | Free testosterone |
| Low SHBG | — | Obesity, hypothyroidism, nephrotic syndrome | Free testosterone |
In the full version for subscribers
- A simple algorithm
- Memory aid
- Exam traps
- 5 review cards
- Enough for IMLE
The full version is open to subscribers of: Urology, Medical licensing exam (IMLE), Internal medicine, Family medicine.
Subscriber? Read the full topic Plans and prices 25 free questions
Sources
- AUA Guideline: Evaluation and Management of Testosterone Deficiency, 2018 — Diagnosis, treatment and monitoring
- EAU Guidelines on Sexual and Reproductive Health, 2025 edition — Male hypogonadism
- Endocrine Society Clinical Practice Guideline: Testosterone Therapy in Men With Hypogonadism, 2018 — Diagnosis and monitoring
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.