Polyuria resident survival guide

Jump to navigation Jump to search
Polyuria Resident Survival Guide Microchapters

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Zaida Obeidat, M.D.

Synonyms and keywords: Approach to polyuria, Approach to dilute urine, Polyuria management, Polyuria work-up



Life Threatening Causes

  • Life-threatening causes include conditions that may result in death or permanent disability within 24 hours if left untreated.
  • Polyuria does not have life-threatening causes.

Common causes [2] [3]

Approach to Polyuria

Shown below is an algorithm summarizing the approach to polyuria.
Abbreviations: DI: Diabetes insipidus;

Hypotonic Polyuria

Suspected hypotonic polyuria[4]
Confirm presence of polyuria
>50ml/kg/24hrs or >3-4L/day
Polyuria confirmed
No polyuria/ or >800 mOsm/kg
Measure urine osmolality
Diabetes insipidus(DI)/Primary polydipsia ruled out
<800 mOsm/kg
Hypotonic polyuria confirmed
Measure serum Sodium and plasma osmolality
Low normal or low serum Sodium <150 mmol/L, plasma osmolality <280 mOsm/kg
Normal serum Sodium/plasma osmolality
High serum Sodium >146 mmol/L, plasma osmolality >300 mOsm/kg
Primary polydipsia
Indeterminate diagnosis
Central or Nephrogenic DI
Water deprivation test
Baseline plasma copeptin
Hypertonic saline infusion test
Urine Osm >800 mOsm/kg
Urine Osm <300 mOsm/kg
Urine Osm 300-800 mOsm/kg
Plasma coprptin >4.9pmol/L
Plasma coprptin <4.9pmol/L
Mild primary polyuria
Desmopressin administration
Urine Osmolality: 300-800 mOsm/Kg and <50% increase
Nephrogenic DI(partial or complete)
Complete Central DI
Therapeutic trial with desmopressin
Primary polydipsia
Partial Nephrogenic DI
Partial Central DI
Initial urine osmolality: 30 mOsm/kg and >50% increase after desmopressin:
Urine osmolality <300 mOsm/kg or <50% increase
Complete Central DI
Complete Nephrogenic DI


Shown below algorithm for the diagnostic approach to polyuria based on the American Journal of Kidney Diseases.

(Urine Output > 3L/d)[5]
Urine Osmolality
Uosm <100mOsm/kg
(Water Diuresis)

*Psychogenic Polydipsia
*DI (central and nephrogenic)
Uosm =100-300mOsm (Mixed Polyuria)
*Partial DI(central and Nephrogenic)
*Simultaneous water and solute intake
Uosm >300mOsm/kg
(Solute Diuresis)

*High solute intake
intravenous fluids
enteral and parenteral nutrition
Exogenous supplements
Water Deprivation Test
24-Hour Urine Collection
(estimation of osmoles)
*Urine sodium
*Urine potassium
*Urine glucose
*Urine urea nitrogen
*Other osmoles


The management of polyuria depends on the underlying cause. Click on each disease shown below to see detailed management for every cause of polyuria.


  • Recommend diet modification, like avoiding any food that irritates the bladder including caffeine, alcohol, carbonated drinks, tomato-based products, chocolate, artificial sweeteners, and spicy foods.
  • Monitor fluid food intake, drink enough to prevent constipation and over-concentration of urine, and avoid drinking just before bedtime.
  • Recommend Kegel exercises to strengthen the muscles around the bladder and urethra.


  1. Moore K, Thompson C, Trainer P (2003). "Disorders of water balance". Clin Med (Lond). 3 (1): 28–33. doi:10.7861/clinmedicine.3-1-28. PMC 4953350. PMID 12617410.
  2. Wieliczko M, Matuszkiewicz-Rowińska J (2013). "[Polyuria]". Wiad Lek. 66 (4): 324–8. PMID 24490488.
  3. Weiss JP, Everaert K (2019). "Management of Nocturia and Nocturnal Polyuria". Urology. 133S: 24–33. doi:10.1016/j.urology.2019.09.022. PMID 31586470.
  4. Feingold KR, Anawalt B, Boyce A, Chrousos G, de Herder WW, Dungan K; et al. (2000). "Endotext". PMID 30779536.
  5. Bhasin B, Velez JC (2016). "Evaluation of Polyuria: The Roles of Solute Loading and Water Diuresis". Am J Kidney Dis. 67 (3): 507–11. doi:10.1053/j.ajkd.2015.10.021. PMID 26687922.