Differential Diagnosis for Erectile Dysfunction, Reduced Ejaculation Volume, and Libido Loss

Given the symptoms of erectile dysfunction, reduced ejaculation volume, and libido loss, with normal bioavailable testosterone levels, the following differential diagnoses are considered:

• Single Most Likely Diagnosis

  • Hypogonadism (despite normal bioavailable testosterone, other aspects of hormone levels or sensitivity could be at play)
  • Justification: Even with normal bioavailable testosterone, issues with testosterone sensitivity, other hormone imbalances (e.g., prolactin, thyroid hormones), or problems with the hypothalamic-pituitary-gonadal axis could lead to these symptoms.

• Other Likely Diagnoses

  • Psychological or psychiatric issues (depression, anxiety, stress)
    • Justification: Mental health issues are common causes of sexual dysfunction, including erectile dysfunction and decreased libido.
  • Medication side effects (antidepressants, antihypertensives, etc.)
    • Justification: Various medications can cause sexual side effects, including decreased libido and erectile dysfunction.
  • Lifestyle factors (smoking, alcohol use, obesity)
    • Justification: These factors can contribute to vascular disease and other conditions that impair sexual function.
  • Sleep disorders
    • Justification: Poor sleep quality can affect hormone levels and contribute to sexual dysfunction.

• Do Not Miss Diagnoses

  • Pituitary tumors (e.g., prolactinoma)
    • Justification: Although rare, these tumors can cause significant hormonal imbalances leading to the described symptoms and are critical to diagnose due to their potential impact on health.
  • Testicular cancer
    • Justification: While less common, testicular cancer can lead to hormonal imbalances and should be considered, especially if there are testicular abnormalities or other suspicious symptoms.
  • Neurological disorders (multiple sclerosis, Parkinson's disease)
    • Justification: Certain neurological conditions can affect sexual function and are important to identify due to their broader health implications.

• Rare Diagnoses

  • Klinefelter syndrome (if not previously diagnosed)
    • Justification: A genetic condition that affects male development and can lead to hypogonadism, though typically diagnosed earlier in life.
  • Prader-Willi syndrome
    • Justification: A rare genetic disorder that can cause hypogonadism among other symptoms.
  • Certain infections (e.g., orchitis, epididymitis)
    • Justification: Infections of the reproductive organs can lead to inflammation and potentially long-term effects on sexual function, though these would typically present with additional symptoms like pain.