Major Causes of Polyuria
| Excessive fluid intake | Nephrogenic diabetes insipidus |
| Primary polydipsia | Lithium exposure |
| Iatrogenic (IV fluids) | Urinary tract obstruction |
| Therapeutic | Papillary necrosis |
| Diuretic agents | Reflux nephropathy |
| Osmotic diuresis | Interstitial nephritis |
| Hyperglycemia | Hypercalcemia |
| Hereditary (V2R, AQP-1/2) | |
| Azotemia | Central diabetes insipidus |
| Mannitol | Tumor |
| Radiocontrast | Postoperative Head trauma Basilar meningitis Neurosarcoidosis |
Abbreviations: AQP, aquaporin; V2R, vasopressin type 2 receptor.