Male Hypogonadism
Male hypogonadism is the clinical syndrome of testosterone deficiency combined with signs and symptoms of androgen insufficiency. It is classified as primary (testicular failure) or secondary (hypothalamic-pituitary dysfunction). Accurate classification guides treatment -- secondary hypogonadism may be treatable with medications that stimulate endogenous testosterone production and preserve fertility.
Symptoms
Low libido, erectile dysfunction, fatigue and reduced energy, depressed mood, decreased muscle mass, increased body fat, reduced bone density, hot flashes, decreased body and facial hair, reduced shaving frequency, and small or softer testes.
Causes and risk
Primary causes include Klinefelter syndrome, cryptorchidism, orchitis, testicular trauma or torsion, and chemotherapy or radiation. Secondary causes include hypothalamic-pituitary tumors, hyperprolactinemia, hemochromatosis, Kallmann syndrome, and functional suppression from obesity, opioid use, and anabolic steroid use.
How it is evaluated
Two early-morning (7 -- 10 AM) total testosterone measurements establish the diagnosis. Free testosterone or bioavailable testosterone is calculated when SHBG may be altered (obesity, aging). LH and FSH differentiate primary from secondary. Prolactin, iron studies, MRI of the pituitary, and genetic testing are added based on clinical context.
Treatment
Testosterone replacement therapy (TRT) is available as topical gels, transdermal patches, subcutaneous pellets, or injections. Clomiphene and hCG stimulate endogenous production and preserve fertility. Underlying causes (hyperprolactinemia, hemochromatosis) are treated directly. We monitor hematocrit, PSA, and testosterone levels during TRT.