Differential Diagnosis for Nocturia with Scant Urine Output

• Single Most Likely Diagnosis
  • Benign Prostatic Hyperplasia (BPH): This condition is common in older men and can cause nocturia due to urinary retention, leading to a sensation of needing to urinate frequently, but with little urine output.
• Other Likely Diagnoses
  • Overactive Bladder: This condition can cause a frequent need to urinate, both during the day and at night, often with small amounts of urine.
  • Urinary Tract Infection (UTI): UTIs can cause irritation to the bladder, leading to frequent urination with little output, especially at night.
  • Diabetes Mellitus: Uncontrolled diabetes can lead to polyuria (frequent urination), which might be perceived as nocturia with little urine output due to the body's attempt to flush out excess glucose.
• Do Not Miss Diagnoses
  • Kidney Failure: Reduced kidney function can lead to a buildup of toxins, causing an increase in urine production, which might be perceived as nocturia. However, in advanced stages, urine output can decrease.
  • Bladder Cancer: Although less common, bladder cancer can cause irritative symptoms such as frequent urination, which might be mistaken for nocturia with little urine output.
  • Obstructive Sleep Apnea: This condition can increase the production of urine at night due to increased pressure on the heart and subsequent release of atrial natriuretic peptide, leading to nocturia.
• Rare Diagnoses
  • Nocturnal Polyuria Syndrome: A condition characterized by an excessive production of urine at night, which can be primary (idiopathic) or secondary to other conditions.
  • Sleep Disorders: Certain sleep disorders can disrupt the normal sleep-wake cycle and lead to increased urine production at night, though these are less directly linked to the symptom of little urine output.