II. Pathophysiology

  1. Water Intoxication, beer potomania, Tea and Toast Syndrome share a similar mechanism for Hyponatremia
    1. Patient with excessive hypoosmolar fluid intake (free water, beer, tea) and low solute diet (low Sodium intake)
    2. Intake exceeds the renal capacity for free water excretion (50 to 100 meq/L or mOsm/L, specific gravity <1.003)
  2. Example: Normal Patient
    1. Patient ingests 600 mOsms solute (e.g. salt, Potassium) per day (10 mOsm/kg/day for a 60 kg person)
    2. If urine most dilute at 50 mEq/L, they could excrete 12 liters worth of free fluid intake without Hyponatremia
    3. However, renal excretion of dilute urine would be overwhelmed at 13 liter intake, and Hyponatremia would begin
  3. Example: Low solute intake (e.g. beer potomania, Tea and Toast Syndrome)
    1. Patient ingests only 100 mOsms solute per day (the remainder is beer, tea)
    2. Renal excretion of dilute urine is overwhelmed at only 2 Liters/day
  4. Example: Exercise Associated Hyponatremia
    1. Extrarenal Solute Losses Replaced with Free Fluid
    2. Excessive extrarenal losses (e.g. sweating) replaced with large volume of free fluid intake

III. Causes

  1. See Exercise Associated Hyponatremia
  2. Water Intoxication (Psychogenic Polydipsia)
    1. Free water intake exceeds free water excretion
    2. Seen in Psychosis (Schizophrenia, Bipolar Disorder)
  3. Beer Potomania Syndrome
    1. Excessive Alcohol intake (esp. beer) and low solute dietary intake
  4. Tea and Toast Syndrome (esp. elderly)
    1. Diet lacking in salt and Protein but with excessive oral free water intake
    2. Compounded by the typically low Glomerular Filtration Rate (GFR) in the elderly (increases fluid reabsorption)
  5. Hypotonic Saline infusion
    1. Affects 4-5% of post-operative patients
  6. Methylenedioxymethamphetamine (MDMA, Ecstasy, Molly)
    1. May result in Water Intoxication to point of severe Hyponatremia (deaths have occurred)

IV. Findings

V. Labs

  1. See Isovolemic Hypoosmolar Hyponatremia
  2. See Hyponatremia
  3. Diagnosis
    1. Hyponatremia
    2. Hypoosmolality
    3. Normal extracellular fluid (normovolemic)
    4. Urine Sodium < 10 (Urine Osmolality <100 mOsm/kg, maximally dilute urine)

VI. Differential Diagnosis

VIII. References

  1. Glaser (2022) EM:Rap 22(6): 9-11
  2. Peechakara (2022) Water Toxicity, StatPearls, Treasure Island, accessed online 6/2/2022
  3. Lodhi (2017) Cureus 9(12): e2000 [PubMed]

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Related Studies

Ontology: Water Intoxication (C0043049)

Definition (MSH) A condition resulting from the excessive retention of water with sodium depletion.
Concepts Disease or Syndrome (T047)
MSH D014869
SnomedCT 71785001
English Water Intoxication, WATER INTOXICATION, WATER INTOX, Water Intoxication [Disease/Finding], water intoxication, Water intoxication, Water intoxication syndrome, Water intoxication syndrome (disorder), intoxication; water, water; intoxication
German WASSERINTOXIKATION, Wasserintoxikation
Japanese 水中毒, ミズチュウドク
Swedish Vattenförgiftning
Czech intoxikace vodou, Intoxikace vodou
Finnish Vesimyrkytys
Portuguese INTOXICACAO HIDRICA, Intoxicação hídrica, Intoxicação por Água
Spanish INTOXICACION ACUOSA, Envenenamiento por Agua, síndrome de hiperhidratación hipotónica (trastorno), síndrome de hiperhidratación hipotónica, Intoxicación hídrica, Intoxicación por Agua
French INTOXICATION PAR L'EAU, Intoxication par l'eau, Intoxication hydrique, Syndrome d'intoxication par l'eau
Polish Zatrucie wodne
Hungarian Víz intoxicatio
Norwegian Vannforgiftning, Vannintoksikasjon
Dutch intoxicatie; water, water; intoxicatie, waterintoxicatie, Intoxicatie, water-, Schwartz-Bartter syndroom, Waterintoxicatie
Italian Intossicazione da acqua

Ontology: Psychogenic polydipsia (C0395005)

Definition (MSH) A clinical disorder characterized by excessive fluid intake (polydipsia); HYPONATREMIA; and POLYURIA in SCHIZOPHRENIA and other psychiatric disorders. Impaired water metabolism in psychogenic polydipsia can result in WATER INTOXICATION.
Concepts Mental or Behavioral Dysfunction (T048)
MSH D059607
SnomedCT 192018009, 82800008, 15945005
German psychogene Polydipsie, Polydipsie, primäre, Polydipsie, primaere, Polydipsie, psychogene, Polydipsie psychogen
Japanese 心因性多飲症, シンインセイタインショウ
English psychogenic water drinking, psychogenic water drinking (diagnosis), Polydipsia psychogenic, psychogenic polydipsia, primary polydipsia, compulsive water drinking, polydipsia psychogenic, Psychogenic Polydipsias, Psychogenic Polydipsia, Polydipsia, Primary, Primary Polydipsias, Polydipsias, Primary, Polydipsia, Psychogenic, Polydipsias, Psychogenic, Primary Polydipsia, Polydipsia, Psychogenic [Disease/Finding], Primary polydipsia, Psychogenic polydipsia (disorder), Psychogenic polydipsia
Czech Polydipsie psychogenní, Psychogenní polydipsie, psychogenní polydipsie, psychogenní žízeň
Hungarian Psychogen polydipsia, Pszihogén polydipsia
French Polydipsie primitive, Potomanie, Polydipsie psychogène, Polydipsie primaire
Portuguese Polidipsia Psicogênica, Polidipsia psicogénica
Spanish Polidipsia Psicogénica, polidipsia primaria (trastorno), polidipsia primaria, polidipsia psicogéna (trastorno), polidipsia psicogéna, polidipsia psicogénica, polidipsia psicógena (trastorno), polidipsia psicógena, Polidipsia psicógena
Polish Polidypsja psychogenna
Italian Polidipsia psicogena, Polidipsia primaria
Norwegian Primær polydipsi, Psykogen polydipsi
Dutch psychogenetische polydipsie