Quantitative changes of urine

One normally produces 500 - 2500 mL of urine per day. In case of pathology, the amount may be increased or decreased.

Polyuria refers to pathologically increased amount of urine (> 2500 mL/day) or > 50 mL per kg of bodyweight per hour. It's a relatively rare finding.

Oliguria refers to decreased amount of urine (100 - 500 mL/day) or < 20 mL/hour or < 0.5 mL per kg of bodyweight per hour.

Anuria refers to having < 100 mL of urine during a day.

Causes

  • Polyuria
    • Diabetes insipidus
    • Diabetes mellitus
    • Diuretics
    • Primary polydipsia (psychogenic)
  • Oliguria
    • Due to acute kidney injury
    • Prerenal causes
      • Dehydration
      • Heart failure
      • Renal artery stenosis
    • Intrarenal causes
      • Acute tubular necrosis
      • Acute or chronic glomerulonephritis
      • Acute interstitial nephritis
    • Postrenal causes
      • Obstruction
  • Anuria
    • Generally same as for anuria, but more severe