Why have my testes suddenly descended and my erections lost rigidity over the past week—is this due to testicular atrophy or another underlying pathology?

Sudden Testicular Descent and Erectile Changes: Clinical Assessment

Your sudden onset of low-hanging testicles and loss of testicular retraction during erections over just one week is NOT consistent with testicular atrophy—this presentation suggests an acute neuromuscular or hormonal disruption affecting the cremasteric reflex and dartos muscle function, not structural testicular disease.

Why This Is Not Testicular Atrophy

Testicular atrophy develops gradually over months to years, not suddenly over one week. 1 True atrophy involves progressive loss of testicular volume (typically <12 mL), elevated FSH levels (>7.6 IU/L), and impaired spermatogenesis—none of which occur acutely. 1, 2 The time course you describe is completely incompatible with atrophic processes, which result from chronic conditions like cryptorchidism, Klinefelter syndrome, prior chemotherapy, or prolonged anabolic steroid use. 1, 3

What Actually Controls Testicular Position

• The cremasteric muscle contracts reflexively to elevate the testes in response to cold, touch, or sexual arousal—this is a spinal reflex mediated by the genitofemoral nerve. 4
• The dartos muscle in the scrotal wall contracts to wrinkle the scrotum and draw the testes closer to the body, regulated by temperature and autonomic tone.
• During erections, normal testicular elevation occurs due to cremasteric contraction and increased pelvic floor muscle tone—loss of this response indicates neuromuscular dysfunction, not testicular pathology. 5

Acute Causes of Loss of Cremasteric Function

Neurological Disruption

• Genitofemoral nerve injury or compression from recent inguinal trauma, heavy lifting, or prolonged sitting can acutely abolish the cremasteric reflex. 4
• Lumbar radiculopathy (L1-L2) from disc herniation or spinal stenosis may present with unilateral or bilateral loss of cremasteric function.

Hormonal/Metabolic Causes

• Acute hypogonadism from sudden cessation of anabolic steroids, opioid initiation, or pituitary dysfunction can reduce dartos muscle tone within days. 1, 3
• Hypothyroidism causes generalized smooth muscle relaxation and loss of scrotal tone.

Medication Effects

• Alpha-blockers (tamsulosin, doxazosin) for urinary symptoms relax smooth muscle and can cause scrotal laxity.
• Antihypertensives (especially calcium channel blockers) may reduce vascular tone and dartos contraction.
• Opioids or sedatives suppress autonomic reflexes including cremasteric responses.

Erectile Rigidity and Testicular Retraction

The loss of testicular elevation during erections suggests impaired pelvic floor muscle coordination or reduced intracavernosal pressure. 5 Axial penile rigidity depends on intracavernosal pressure, tunical distensibility, and penile geometry—not testicular function. 5 However, the simultaneous loss of both erectile rigidity and testicular retraction points to a shared neurovascular or hormonal mechanism rather than isolated penile pathology. 5, 6

Immediate Diagnostic Steps

History to Obtain

• Recent medication changes including alpha-blockers, antihypertensives, opioids, or cessation of testosterone/anabolic steroids. 1, 3
• Inguinal or lower back trauma from heavy lifting, falls, or prolonged cycling/sitting.
• Systemic symptoms including fatigue, cold intolerance (hypothyroidism), or visual changes (pituitary lesion).
• Prior cryptorchidism or testicular surgery which increases risk of late complications. 7

Physical Examination

• Palpate testicular size and consistency using a Prader orchidometer—volumes <12 mL suggest atrophy, but acute changes are unlikely. 1, 2
• Assess cremasteric reflex by stroking the inner thigh—absence bilaterally suggests neurologic pathology; unilateral absence suggests localized nerve injury. 4
• Check for inguinal masses or hernias that could compress the genitofemoral nerve.
• Evaluate secondary sexual characteristics including body hair distribution and gynecomastia to screen for hypogonadism. 7, 3

Laboratory Evaluation

• Morning serum testosterone, FSH, and LH (drawn 08:00–10:00 h on two separate occasions) to distinguish primary testicular failure from secondary hypogonadism. 1, 3
• Thyroid-stimulating hormone (TSH) to exclude hypothyroidism.
• Prolactin if testosterone is low with low/normal LH, suggesting pituitary dysfunction. 3

Imaging

• Scrotal ultrasound with Doppler is indicated if testicular size discrepancy >2 mL or 20%, or if masses are palpable—but is NOT needed for acute cremasteric dysfunction alone. 1, 2
• Lumbar spine MRI if radiculopathy is suspected based on back pain or lower extremity symptoms.

Critical Red Flags Requiring Urgent Evaluation

• Sudden unilateral testicular pain or swelling suggests torsion or epididymitis—requires emergency scrotal ultrasound. 7
• Bilateral testicular pain with systemic illness may indicate autoimmune orchitis or vasculitis.
• Progressive erectile dysfunction with visual field defects or headaches suggests pituitary macroadenoma—requires brain MRI. 3
• History of cryptorchidism with new testicular mass mandates urgent urology referral due to 3.6–7.4 times higher cancer risk. 1

Management Algorithm

1. If recent medication changes: Discuss with prescriber about alternative agents or dose adjustment.
2. If anabolic steroid cessation: Expect gradual recovery over 3–12 months; consider hCG therapy to accelerate testosterone recovery if fertility is desired. 3
3. If neurologic symptoms: Obtain lumbar spine imaging and neurology referral.
4. If hormonal abnormalities: Endocrinology referral for hypogonadism or thyroid dysfunction management.
5. If no clear cause identified: Urology referral for comprehensive evaluation including nocturnal penile tumescence testing to distinguish organic from psychogenic erectile dysfunction. 7

Common Pitfalls to Avoid

• Do not assume atrophy based on position alone—true atrophy requires documented volume loss <12 mL and elevated FSH. 1, 2
• Do not start testosterone replacement without fertility assessment—exogenous testosterone suppresses spermatogenesis and can cause azoospermia lasting months to years. 1, 3
• Do not dismiss acute changes as "normal aging"—sudden onset over one week always warrants investigation.
• Do not order testicular biopsy without clear indication—it is reserved for cancer risk stratification (age <30 years, volume <12 mL, cryptorchidism history) or azoospermia workup, not for positional changes. 1, 3