Guideline Summary for Diagnosis and Management of Severe Male Hypogonadism

Definition and Diagnostic Thresholds

Severe hypogonadism is identified by a free testosterone concentration far below the lower limit of normal (e.g., ~7 pg/mL), which mandates immediate diagnostic evaluation and likely testosterone replacement therapy. 1
The American College of Endocrinology defines hypogonadism as a free testosterone level below the lower limit of normal for healthy young adult men. 3

Repeat a fasting morning free testosterone measurement (7–11 AM) using equilibrium dialysis or calculation from total testosterone and SHBG to confirm the low result. 5
Simultaneously obtain luteinizing hormone (LH) and follicle‑stimulating hormone (FSH) levels:
- Low/normal LH ± FSH suggests secondary (central) hypogonadism.
- Elevated LH ± FSH indicates primary (testicular) hypogonadism. 1

Measure serum prolactin to detect hyperprolactinemia, which can suppress gonadotropins. 3
Assess iron saturation to screen for hemochromatosis as a reversible cause. 1
If total testosterone is <150 ng/dL or pan‑hypopituitarism is suspected, evaluate additional pituitary hormones (TSH, free T4, cortisol, IGF‑1). 1
Obtain pituitary magnetic resonance imaging when secondary hypogonadism is severe, prolactin remains elevated, or neurologic symptoms (headache, visual changes) are present. 1
Review for suppressive factors such as acute illness, recent surgery, opioid or high‑dose glucocorticoid use, eating disorders, or excessive exercise. 1

Perform karyotype analysis to exclude Klinefelter syndrome (47,XXY). 1
Take a focused history for prior mumps orchitis, testicular trauma, autoimmune orchitis, or congenital conditions (e.g., Kallmann syndrome, myotonic dystrophy). 3

Screen for typical hypogonadal symptoms (decreased libido, erectile dysfunction, low energy, mood changes, reduced muscle mass/strength, hot flashes). 1
Evaluate comorbidities that frequently coexist with hypogonadism: diabetes mellitus, obesity, metabolic syndrome, and cardiovascular disease. 7
Order a bone‑density (DXA) scan because severe androgen deficiency predisposes to osteoporosis. 1
Obtain a complete blood count to detect normochromic, normocytic anemia. 3
If fertility is a concern, perform a semen analysis. 1

TRT is indicated in young adults with unequivocally low free testosterone and confirmed hypogonadism, aiming to restore secondary sexual characteristics, sexual function, well‑being, muscle mass, and bone density. 3
Treatment goals include achieving testosterone concentrations in the mid‑normal adult range. 8

Active or prior breast or prostate cancer. 8
Palpable prostate nodule or prostate‑specific antigen (PSA) >3 ng/mL (some guidelines use >4 ng/mL). 5
Hematocrit >50 %. 5
Untreated severe obstructive sleep apnea. 5
Severe lower urinary tract symptoms (International Prostate Symptom Score >19). 8
Uncontrolled or poorly controlled heart failure. 5

Prescribe FDA‑approved testosterone products (intramuscular injections, transdermal gels/patches, or subcutaneous pellets) rather than compounded formulations. 9
For patients desiring fertility preservation, consider alternatives such as human chorionic gonadotropin, selective estrogen receptor modulators (e.g., clomiphene), or aromatase inhibitors instead of exogenous testosterone. 9

Measure total testosterone after an appropriate interval to verify target levels are reached. 9
Re‑assess testosterone concentrations every 6–12 months. 9
Regularly monitor hematocrit, PSA, and clinical symptom response. 5
If target testosterone is attained but symptoms persist after 3–6 months, consider discontinuing therapy. 9

Do not diagnose hypogonadism during an acute illness, as systemic stress can transiently lower testosterone levels. 1
In men under 30 years, markedly low testosterone is pathologic rather than age‑related; a thorough workup is essential. 3
Exogenous testosterone suppresses spermatogenesis; discuss fertility preservation before initiating therapy. 9
While borderline testosterone levels may merit a therapeutic trial, unequivocally low values (as described) require treatment without a trial period. 3