What could be causing my low libido, erectile dysfunction (ED), decreased semen volume, and thicker semen?

Evaluation and Management of Low Libido, Erectile Dysfunction, and Decreased/Thickened Semen Volume

Immediate Diagnostic Workup

You need morning total testosterone measured on two separate occasions, along with FSH and prolactin levels, as this constellation of symptoms strongly suggests hypogonadism. 1

• Measure morning total testosterone on two separate days, as testosterone levels fluctuate and diagnosis requires persistent deficiency 1
• Check FSH to distinguish primary hypogonadism (elevated FSH) from secondary hypogonadism (low/normal FSH), which is potentially reversible 1
• Measure serum prolactin in all men with reduced libido and erectile dysfunction combined with low testosterone, as hyperprolactinemia causes this exact symptom constellation 1
• If total testosterone is borderline, check SHBG levels, since elevated SHBG reduces bioavailable testosterone and can cause functional hypogonadism despite normal total testosterone 1

Physical Examination Findings to Document

• Palpate bilaterally for vas deferens to rule out congenital bilateral absence of vas deferens (CBAVD) 2
• Assess testicular size and consistency—normal-sized testes suggest obstruction while atrophic testes indicate spermatogenic failure 2
• Perform digital rectal examination to assess prostate size and consistency 2
• Examine for palpable varicoceles, as treatment of clinical varicoceles improves semen parameters 2

Semen Analysis and Additional Testing

• Check semen pH, as acidic semen (pH <7.0) with low volume strongly suggests ejaculatory duct obstruction or CBAVD 2, 3
• Perform post-ejaculatory urinalysis when volume <1 mL (except in bilateral vasal agenesis or hypogonadism) to diagnose retrograde ejaculation 2
• Measure semen volume—normal is ≥1.4 mL; volumes below this threshold require investigation for structural causes 2

Medication Review for Iatrogenic Causes

• Review all medications for drugs that suppress the hypothalamic-pituitary-gonadal axis, such as opiates, glucocorticoids, anabolic steroids, and GnRH agonists/antagonists 1
• 5α-reductase inhibitors (finasteride, dutasteride) commonly cause reduced libido, erectile dysfunction, ejaculation disorders, and decreased semen volume 4
• Alpha-1 blockers do not affect libido but cause ejaculatory dysfunction, especially tamsulosin and silodosin 4
• Finasteride 5 mg/day is associated with reduced semen volume 2

Interpretation of Hormone Results and Next Steps

If Testosterone is Low with Low/Normal FSH (Secondary Hypogonadism)

• Order MRI of the pituitary if prolactin is elevated to evaluate for prolactinoma or other pituitary masses 1
• Treat the underlying cause of hyperprolactinemia, such as discontinuing prolactin-elevating medications or treating prolactinoma with dopamine agonists 1
• Hyperprolactinemia directly suppresses libido and causes erectile dysfunction independent of testosterone levels 1

If Testosterone is Low with Elevated FSH (Primary Hypogonadism)

• This indicates testicular failure and is generally not reversible 1
• Testosterone replacement therapy is appropriate if fertility is not desired 1

Structural Causes of Low Semen Volume

Ejaculatory Duct Obstruction (EDO)

• EDO presents with acidic semen (pH <7.0), volume <1.4 mL, azoospermia or severe oligospermia, normal testosterone, and palpable vas deferens 1, 2
• Order TRUS or pelvic MRI only when clinical criteria for EDO are met—do not perform as part of routine initial evaluation 2, 3
• Transurethral resection of ejaculatory ducts (TURED) is the definitive treatment for confirmed EDO on TRUS or MRI showing dilated seminal vesicles and ejaculatory ducts 2, 3

Congenital Bilateral Absence of Vas Deferens (CBAVD)

• CBAVD can be diagnosed by physical examination alone when vas deferens are not palpable bilaterally 3
• No medical or surgical treatment restores ejaculatory volume; proceed directly to sperm retrieval (TESE/MESA) with ICSI for fertility 2, 3
• CFTR gene testing for the female partner is mandatory before proceeding with assisted reproduction 2, 3

Varicocele

• Treatment is indicated for palpable varicoceles with abnormal semen parameters 2, 3
• Varicocelectomy improves semen parameters and may restore sperm in ejaculate for men with azoospermia 2, 3
• Do not treat subclinical (non-palpable) varicoceles, as this does not improve semen parameters or fertility rates 2, 3

Treatment Algorithm Based on Etiology

If Hypogonadism is Confirmed and Fertility is NOT Desired

• Testosterone replacement therapy normalizes libido, improves erectile function, and enhances quality of life in men with secondary hypogonadism without fertility concerns 1
• Intramuscular formulations are preferred over transdermal formulations when initiating testosterone treatment, as costs are considerably lower and clinical effectiveness and harms are similar 4
• Reevaluate symptoms within 12 months and periodically thereafter; discontinue testosterone treatment if there is no improvement in sexual function 4

If Hypogonadism is Confirmed and Fertility IS Desired

• Never initiate testosterone replacement therapy in men desiring fertility, as it suppresses spermatogenesis and can cause azoospermia 1, 2
• Refer to reproductive endocrinology for gonadotropin therapy or other fertility-preserving treatments 1

If Testosterone is Normal

• Consider tadalafil 5 mg daily, the only PDE5 inhibitor licensed for treatment of male lower urinary tract symptoms and erectile dysfunction 4
• Tadalafil decreased sperm concentrations in studies of 10 mg for 6 months and 20 mg for 9 months, but this effect was not seen in the study of 20 mg for 6 months 5
• Tadalafil had no adverse effect on mean concentrations of testosterone, luteinizing hormone, or follicle stimulating hormone 5
• Psychosexual therapy may be used in conjunction with physical therapies and shows successful outcomes in 50-80% of patients 4

Lifestyle and Risk Factor Modification

• Obesity decreases testosterone and SHBG, worsens erectile function, and is a modifiable factor that worsens sexual function 1
• Smoking is associated with reduced fertility and erectile dysfunction; cessation is recommended 1
• Alcohol consumption results in slightly lower semen volume and slightly poorer sperm morphology 2
• Anabolic steroid use is associated with reduced fertility and should be discontinued 2

Genetic Testing Before Assisted Reproduction

• Karyotype testing is mandatory for azoospermia or severe oligospermia (<5 million/mL) 1, 2, 3
• Y-chromosome microdeletion analysis is required for azoospermia or sperm concentration <1 million/mL 1, 2, 3
• Genetic counseling should precede ICSI, as genetic abnormalities may be transmitted to offspring 2, 3

Critical Pitfalls to Avoid

• Do not attribute low semen volume to stress alone—stress is associated with reduced sperm progressive motility but has no association with semen volume 2
• Do not use ultrasound to hunt for subclinical varicoceles—only palpable varicoceles benefit from treatment 2, 3
• Do not delay genetic testing—results impact counseling and treatment decisions before proceeding with assisted reproduction 2, 3
• Do not routinely order TRUS or pelvic MRI as part of initial evaluation—reserve for cases with clear clinical suspicion of EDO 2, 3
• A history of decreased libido and/or testicular atrophy on physical examination cannot predict hypogonadism, so laboratory testing is mandatory 6