What could be causing my sudden onset of erectile dysfunction (ED), yellow semen, low semen volume, low libido, and testicular atrophy, and how should it be treated?

Urgent Evaluation for Testicular Atrophy and Sexual Dysfunction

You need immediate medical evaluation with morning serum total testosterone, FSH, prolactin, and semen analysis to determine if you have primary testicular failure, infection-related damage, or an obstructive process—testicular atrophy with this constellation of symptoms suggests serious underlying pathology that requires urgent workup. 1

Critical First Steps

Obtain these laboratory tests immediately:

• Morning (7-11 AM) serum total testosterone to assess for hypogonadism (normal >300 ng/dL) 1, 2
• FSH level to distinguish primary testicular failure (elevated FSH >7.6 IU/L with atrophy) from secondary causes 1
• Prolactin level if testosterone is low or libido severely decreased 3, 4
• Semen analysis to evaluate for infection (yellow semen suggests pyospermia/infection), volume abnormalities, and sperm parameters 1
• Urinalysis and urine culture if infection suspected based on semen color 1

Understanding Your Symptoms

Testicular atrophy with elevated FSH (>7.6 IU/L) indicates primary testicular failure (non-obstructive azoospermia), which causes low testosterone, ED, and low libido. 1 This pattern suggests the testes themselves are damaged and cannot produce adequate testosterone or sperm.

Yellow semen with low volume may indicate:

• Genital tract infection (epididymitis, prostatitis) causing pyospermia 1
• Distal obstruction if volume is very low (<1.4 mL) with acidic pH, though this typically doesn't cause testicular atrophy 1

The sudden onset of all symptoms together strongly suggests either:

• Severe infection (orchitis, epididymo-orchitis) that damaged testicular tissue 1
• Primary hypogonadism from testicular failure 2, 3
• Klinefelter syndrome or other genetic cause if atrophy is bilateral and longstanding 1

Diagnostic Algorithm

If FSH >7.6 IU/L with testicular atrophy:

• This confirms primary testicular failure (non-obstructive azoospermia) 1
• Obtain karyotype testing to rule out Klinefelter syndrome (47,XXY), especially if sperm count <5 million/mL 1
• Y-chromosome microdeletion testing if severely oligospermic (0-5 million/mL) 1

If FSH <7.6 IU/L with normal-sized testes:

• Consider secondary hypogonadism (pituitary/hypothalamic cause) 1
• Check LH, prolactin, thyroid function 4

If semen analysis shows infection:

• Treat with appropriate antibiotics based on culture 1
• Re-evaluate testosterone and symptoms after infection clears

Treatment Approach

If Testosterone Deficiency Confirmed (<300 ng/dL)

Start testosterone replacement therapy first, as this addresses both ED and low libido in hypogonadal men. 5, 2 The Endocrine Society recommends treating testosterone deficiency before or concurrent with ED-specific therapy. 2

After testosterone optimization (or if testosterone normal), initiate PDE5 inhibitor:

• Sildenafil 50-100mg, tadalafil 10-20mg, or vardenafil 10-20mg 5, 2
• Start conservatively and titrate to maximum dose 1, 2
• Requires at least 5 attempts at maximum dose before declaring failure 2
• Effective in 60-65% of men with ED 2

Cardiovascular Risk Assessment Required

ED is a risk marker for cardiovascular disease—you need cardiac evaluation even without symptoms. 1, 2 Obtain blood pressure, BMI, fasting glucose, HbA1c, lipid profile, and resting ECG before starting treatment. 5, 2

Lifestyle Modifications (Start Immediately)

• Smoking cessation (if applicable) 5, 2
• Weight loss if BMI >25 kg/m² 5, 2
• Regular aerobic exercise 5, 2
• Limit alcohol to <21 units/week 5
• Mediterranean diet 5

Critical Pitfalls to Avoid

Do not assume this is "just psychological"—the combination of testicular atrophy, yellow semen, and sudden onset demands organic workup. 1, 2, 6 Sudden onset can indicate infection or acute testicular damage, not just psychogenic causes. 6

Do not delay testosterone testing—the combination of ED with low libido makes testosterone deficiency highly likely. 2, 3 A history of decreased libido specifically points toward hormonal causes. 2, 3

Do not ignore the yellow semen—this may indicate active infection requiring antibiotic treatment. 1 Untreated genital tract infections can cause permanent testicular damage and infertility.

Do not rely on a single testosterone measurement—repeat morning testing is essential for confirmation. 5, 2 Single measurements can be misleading due to diurnal variation.

If you desire future fertility, do not start testosterone replacement without discussing sperm banking first—exogenous testosterone suppresses sperm production. 1 This is critical if testicular function is already compromised.

When to Refer to Urology

Refer immediately if:

• Testicular atrophy is confirmed on physical examination 1
• Semen analysis shows severe oligospermia (<5 million/mL) or azoospermia 1
• Yellow semen persists despite antibiotic treatment 1
• Two different PDE5 inhibitors fail at maximum dose 2

Physical examination by a urologist should assess:

• Testicular size and consistency (atrophy suggests volume <15 mL) 1
• Epididymal induration or dilation (suggests obstruction or chronic infection) 1
• Presence/absence of vas deferens 1

Prognosis Considerations

If primary testicular failure is confirmed, testosterone replacement will improve ED and libido but will not restore testicular size or fertility. 1, 2 The atrophy may be permanent depending on the underlying cause and duration. 7

If infection is the cause and treated early, some recovery of testicular function may occur, but prolonged infection can cause irreversible damage. 1