====== Hyponatremia ======

  * Hyponatremia is defined as serum sodium less than 136 mmol/L.
  * Can be classified as hypotonic, isotonic, or hypertonic. 

//([[#references|Adrogué 2000]])//

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===== Causes =====

==== Renal ====

  * [[Kidney failure]]: acute or chronic; **//hyper//**volemic
  * [[Nephrotic syndrome]]: **//hyper//**volemic
  * [[Renal tubular acidosis]] (RTA): **//hypo//**volemic

//([[#references|Braun 2015]], [[#references|Milionis 2002]])//

==== Fluid loss ====

  * [[Burn]]: **//hypo//**volemic
  * [[Diarrhea]]: **//hypo//**volemic
  * [[Ileus]]: **//hypo//**volemic
  * [[Vomiting]]: **//hypo//**volemic

//([[#references|Braun 2015]], [[#references|Milionis 2002]])//

==== Infectious ====

  * [[Peritonitis]]
  * [[Sepsis]]

//([[#references|Braun 2015]], [[#references|Milionis 2002]])//

==== Drug induced ====

  * [[Beer potomania]]: **//eu//**volemic
  * [[Ecstasy]] use: **//eu//**volemic
  * [[Loop diuretics]]: **//hypo//**volemic
  * [[Osmotic diuresis]]: glucose, mannitol, urea; **//hypo//**volemic
  * [[Thiazide diuretics]]: **//hypo//**volemic
  * [[Water intoxication]]: **//eu//**volemic

//([[#references|Braun 2015]], [[#references|Milionis 2002]])//

==== Endocrine ====

  * [[Adrenal insufficiency]] (Addison's disease): **//hypo//**volemic
  * [[Cerebral salt-wasting syndrome]] (CSWS): rare; **//hypo//**volemic
  * [[Hypothyroidism]]: **//eu//**volemic
  * [[Mineralocorticoid Deficiency]]: **//hypo//**volemic
  * [[Reset osmostat]]: **//eu//**volemic
  * [[Syndrome of inappropriate antidiuretic hormone secretion]] (SIADH): **//eu//**volemic

//([[#references|Braun 2015]], [[#references|Milionis 2002]])//

==== Psychiatric ====

  * [[Primary polydipsia]] (psychogenic polydipsia): **//eu//**volemic

//([[#references|Braun 2015]], [[#references|Milionis 2002]])//

==== Multiorgan ====

  * [[Heart failure]]: **//hyper//**volemic
  * [[Liver disease]]: **//hyper//**volemic
  * [[Pregnancy]]: mild can be normal //([[#references|Plant 2014]])//
  * [[Pre-eclampsia]]

//([[#references|Braun 2015]], [[#references|Milionis 2002]])//

==== Pseudohyponatremia ====

  * [[Hyperglycemia]]
  * [[Hyperlipidemia]]
  * [[Hyperproteinemia]]
  * [[Paraproteinemia]]
  * [[Laboratory error]]

//([[#references|Braun 2015]], [[#references|Milionis 2002]])//

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===== Further reading =====

==== Internal ====

  * [[Electrolyte imbalance]]

==== External ====

  * [[|Diagnosis and management of hyponatremia and hypernatremia]] (American Academy of Family Physicians)

----

===== References =====

  * **Adrogué** HJ, Madias NE. [[https://www.nejm.org/doi/full/10.1056/NEJM200005253422107|Hyponatremia]]. N Engl J Med **2000**;342:1581-1589. DOI: [[https://doi.org/10.1056/NEJM200005253422107|10.1056/NEJM200005253422107]]
  * **Braun** MM, Barstow CH, Pyzocha NJ. [[https://www.aafp.org/afp/2015/0301/p299.html|Diagnosis and Management of Sodium Disorders: Hyponatremia and Hypernatremia]]. Am Fam Physician. **2015**;91(5):299-307.
  * **Milionis** HJ, Liamis GL, Elisaf MS. [[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC100882/|The hyponatremic patient: a systematic approach to laboratory diagnosis]]. CMAJ. **2002**;166(8):1056–1062.
  * **Plant** TM, Zeleznik AJ. (**2014**). Knobil and Neill's Physiology of Reproduction. Academic Press. p. 1962. ISBN 978-0123977694.


{{tag>Nephrology Endocrinology Kidney Conditions_and_diseases Article}}