Differential Diagnosis for Low Urine Output

• Single most likely diagnosis:
  • Acute Kidney Injury (AKI): This is a common cause of low urine output, especially in hospitalized patients or those with underlying medical conditions. AKI can result from various factors such as dehydration, medication side effects, or obstructive causes.
• Other Likely diagnoses:
  • Dehydration: Inadequate fluid intake or excessive fluid loss can lead to decreased urine output. This is a common and often reversible cause.
  • Urinary Retention: Obstruction of the urinary tract, which can be due to benign prostatic hyperplasia, kidney stones, or other causes, can significantly reduce urine output.
  • Sepsis: Systemic infection can lead to decreased urine output due to hypoperfusion of the kidneys.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
  • Post-Renal Acute Kidney Injury (obstruction): This includes conditions such as kidney stones or tumors that obstruct the urinary tract, which can lead to severe kidney damage if not promptly addressed.
  • Rhabdomyolysis: Muscle breakdown can release myoglobin into the bloodstream, leading to kidney damage and decreased urine output. This condition requires immediate intervention.
  • Severe Hypovolemia: Significant blood or fluid loss can lead to inadequate kidney perfusion, resulting in low urine output.
• Rare diagnoses:
  • Prerenal causes such as heart failure or liver disease: While less common, these conditions can lead to decreased effective circulating volume and subsequently low urine output.
  • Certain medications or toxins: Some medications and toxins can directly affect kidney function, leading to decreased urine output.
  • End-stage renal disease: Advanced kidney disease can result in a permanent decrease in kidney function, manifesting as low urine output.