Highlights & Basics
- Hyponatremia is the most common electrolyte disorder encountered in clinical practice.
- Can occur in settings of volume depletion, volume overload, or euvolemia.
- Serum osmolality, urine osmolality, and urine sodium concentration help to determine the underlying cause.
- Cerebral edema is a medical emergency and occurs more frequently when hyponatremia develops over <48 hours. Patients should be treated promptly with hypertonic 3% saline.
- Other treatment depends on the underlying cause and may include fluid restriction and stopping causative medications.
Quick Reference
History & Exam
Key Factors
Other Factors
Diagnostics Tests
Treatment Options
Definition
Epidemiology
Etiology
Pathophysiology
Images
Potential etiologies of hypotonic hyponatremia based on volume status of patient. CNS, central nervous system; SIADH, syndrome of inappropriate antidiuretic hormone
Algorithm for the diagnosis of hypotonic hyponatremia. SIADH, syndrome of inappropriate antidiuretic hormone
Etiologies of hypotonic hyponatremia (serum osmolality <275 mOsm/kg). SIADH, syndrome of inappropriate antidiuretic hormone
Brain magnetic resonance imaging of a patient with central pontine myelinolysis showing hypointensity within the basis pontis
Brain magnetic resonance imaging of a patient with central pontine myelinolysis showing: (a) trident-shaped hyperintensity within the pons; (b) hypointensity within the basis pontis; and (c) hyperintense focus in the central pons
Citations
Spasovski G, Vanholder R, Allolio B, et al; Hyponatraemia Guideline Development Group. Clinical practice guideline on diagnosis and treatment of hyponatraemia. Eur J Endocrinol. 2014 Feb 25;170(3):G1-47.[Abstract][Full Text]
Adrogué HJ, Tucker BM, Madias NE. Diagnosis and management of hyponatremia: a review. JAMA. 2022 Jul 19;328(3):280-91.[Abstract]
Verbalis JG, Grossman A, Höybye C, et al. Review and analysis of differing regulatory indications and expert panel guidelines for the treatment of hyponatremia. Curr Med Res Opin. 2014 Jul;30(7):1201-7.[Abstract]
Hoorn EJ, Zietse R. Diagnosis and treatment of hyponatremia: compilation of the guidelines. J Am Soc Nephrol. 2017 May;28(5):1340-9.[Abstract][Full Text]
1. Lawless SJ, Thompson C, Garrahy A. The management of acute and chronic hyponatraemia. Ther Adv Endocrinol Metab. 2022 May 14;13:20420188221097343.[Abstract][Full Text]
2. Spasovski G, Vanholder R, Allolio B, et al; Hyponatraemia Guideline Development Group. Clinical practice guideline on diagnosis and treatment of hyponatraemia. Eur J Endocrinol. 2014 Feb 25;170(3):G1-47.[Abstract][Full Text]
3. Adrogué HJ, Tucker BM, Madias NE. Diagnosis and management of hyponatremia: a review. JAMA. 2022 Jul 19;328(3):280-91.[Abstract]
4. Adrogué HJ, Madias NE. The syndrome of inappropriate antidiuresis. N Engl J Med. 2023 Oct 19;389(16):1499-509.
5. Ball S, Barth J, Levy M, et al. Society for Endocrinology endocrine emergency guidance: emergency management of severe symptomatic hyponatraemia in adult patients. Endocr Connect. 2016 Sep;5(5):G4-6.[Abstract][Full Text]
6. Giordano M, Ciarambino T, Castellino P, et al. Diseases associated with electrolyte imbalance in the ED: age-related differences. Am J Emerg Med. 2016 Oct;34(10):1923-1926.[Abstract][Full Text]
7. Wald R, Jaber BL, Price LL, et al. Impact of hospital-associated hyponatremia on selected outcomes. Arch Intern Med. 2010 Feb 8;170(3):294-302.[Abstract]
8. Zilberberg MD, Exuzides A, Spalding J, et al. Epidemiology, clinical and economic outcomes of admission hyponatremia among hospitalized patients. Curr Med Res Opin. 2008 Jun;24(6):1601-8.[Abstract]
9. Verbalis JG, Grossman A, Höybye C, et al. Review and analysis of differing regulatory indications and expert panel guidelines for the treatment of hyponatremia. Curr Med Res Opin. 2014 Jul;30(7):1201-7.[Abstract]
10. Funk GC, Lindner G, Druml W, et al. Incidence and prognosis of dysnatremias present on ICU admission. Intensive Care Med. 2010 Feb;36(2):304-11.[Abstract]
11. Braun MM, Barstow CH, Pyzocha NJ. Diagnosis and management of sodium disorders: hyponatremia and hypernatremia. Am Fam Physician. 2015 Mar 1;91(5):299-307.[Abstract][Full Text]
12. Freda BJ, Davidson MB, Hall PM. Evaluation of hyponatremia: a little physiology goes a long way. Cleve Clin J Med. 2004 Aug;71(8):639-50.[Abstract]
13. Moen V, Brudin L, Rundgren M, et al. Hyponatremia complicating labour - rare or unrecognised? A prospective observational study. BJOG. 2009 Mar;116(4):552-61.[Abstract][Full Text]
14. Morton A, Lumchee M, Kumar S, et al. Pregnancy outcomes in women with hyponatraemia and preeclampsia: case series and literature review. Pregnancy Hypertens. 2021 Dec;26:38-41.[Abstract]
15. Friedman E, Shadel M, Halkin H, et al. Thiazide-induced hyponatremia: reproducibility by single dose rechallenge and an analysis of pathogenesis. Ann Intern Med. 1989 Jan 1;110(1):24-30.[Abstract]
16. Bennett BL, Hew-Butler T, Rosner MH, et al. Wilderness Medical Society clinical practice guidelines for the management of exercise-associated hyponatremia: 2019 update. Wilderness Environ Med. 2020 Mar;31(1):50-62.[Abstract][Full Text]
17. Grant P, Ayuk J, Bouloux PM, et al. The diagnosis and management of inpatient hyponatraemia and SIADH. Eur J Clin Invest. 2015 Aug;45(8):888-94.[Abstract][Full Text]
18. Jacob S, Spinler SA. Hyponatremia associated with selective serotonin-reuptake inhibitors in older adults. Ann Pharmacother. 2006 Sep;40(9):1618-22.[Abstract]
19. Fabian TJ, Amico JA, Kroboth PD, et al. Paroxetine-induced hyponatremia in older adults: a 12-week prospective study. Arch Intern Med. 2004 Feb 9;164(3):327-32.[Abstract]
20. Wakil A, Ng JM, Atkin SL. Investigating hyponatraemia. BMJ. 2011 Mar 7;342:d1118.[Abstract]
21. Mathus-Vliegen EMH, van der Vliet K, Wignand-van der Storm IJ, et al. Split-dose bowel cleansing with picosulphate is safe and better tolerated than 2-l polyethylene glycol solution. Eur J Gastroenterol Hepatol. 2018 Jul;30(7):709-717.[Abstract][Full Text]
22. Reumkens A, van der Zander Q, Winkens B, et al. Electrolyte disturbances after bowel preparation for colonoscopy: systematic review and meta-analysis. Dig Endosc. 2022 Jul;34(5):913-26.[Abstract][Full Text]
23. Cappola AR, Auchus RJ, El-Hajj Fuleihan G, et al. Hormones and aging: an Endocrine Society scientific statement. J Clin Endocrinol Metab. 2023 Jul 14;108(8):1835-74.[Abstract][Full Text]
24. Adrogué HJ, Madias NE. Hyponatremia. N Engl J Med. 2000 May 25;342(21):1581-9.[Abstract]
25. Shima S, Niimi Y, Moteki Y, et al. Prognostic significance of hyponatremia in acute stroke: a systematic review and meta-analysis. Cerebrovasc Dis. 2020;49(5):531-9.[Abstract][Full Text]
26. Królicka AL, Kruczkowska A, Krajewska M, et al. Hyponatremia in infectious diseases-a literature review. Int J Environ Res Public Health. 2020 Jul 23;17(15):5320.[Abstract][Full Text]
27. Kilpatrick ES. Disorders of sodium balance: hypothyroidism and hyponatraemia: an old wives' tale? BMJ. 2006 Apr 8;332(7545):854.[Abstract][Full Text]
28. Hanna FW, Scanlon MF. Hyponatraemia, hypothyroidism, and role of arginine-vasopressin. Lancet. 1997 Sep 13;350(9080):755-6.[Abstract]
29. Schrier RW. Vasopressin and aquaporin 2 in clinical disorders of water homeostasis. Semin Nephrol. 2008 May;28(3):289-96.[Abstract][Full Text]
30. Warner MH, Holding S, Kilpatrick ES. The effect of newly diagnosed hypothyroidism on serum sodium concentrations: a retrospective study. Clin Endocrinol (Oxf). 2006 May;64(5):598-9.[Abstract]
31. Grohé C, Berardi R, Burst V. Hyponatraemia-SIADH in lung cancer diagnostic and treatment algorithms. Crit Rev Oncol Hematol. 2015 Oct;96(1):1-8.[Abstract]
32. Fiordoliva I, Meletani T, Baleani MG, et al. Managing hyponatremia in lung cancer: latest evidence and clinical implications. Ther Adv Med Oncol. 2017 Nov;9(11):711-9.[Abstract][Full Text]
33. Workeneh BT, Jhaveri KD, Rondon-Berrios H. Hyponatremia in the cancer patient. Kidney Int. 2020 Oct;98(4):870-82.[Abstract]
34. Marquina G, Gomez-Hoyos E, Runkle I. The management of hyponatremia in cancer patients: a practical view in Spain. J Cancer Metastasis Treat. 2020 Mar 10;6:6.[Full Text]
35. Murthy K, Ondrey GJ, Malkani N, et al. The effects of hyponatremia on bone density and fractures: a systemic review and meta-analysis. Endocr Pract. 2019 Apr;25(4):366-78.[Abstract][Full Text]
36. Corona G, Norello D, Parenti G, et al. Hyponatremia, falls and bone fractures: a systematic review and meta-analysis. Clin Endocrinol (Oxf). 2018 Oct;89(4):505-13.[Abstract]
37. Demertzidou E, Zill-E-Huma R, Modi M. Peripartum hyponatraemia: an overview of physiology, prevention and management. Obstet Gynaecol. 2022 May 17; 24(3): 188-94.
38. Wang J, Xu E, Xiao Y. Isotonic versus hypotonic maintenance IV fluids in hospitalized children: a meta-analysis. Pediatrics. 2014 Jan;133(1):105-13.[Abstract]
39. Feld LG, Neuspiel DR, Foster BA, et al. Clinical Practice Guideline: Maintenance Intravenous Fluids in Children. Pediatrics. 2018 Dec;142(6):.[Abstract][Full Text]
40. Hew-Butler T, Rosner MH, Fowkes-Godek S, et al. Statement of the 3rd International exercise-associated hyponatremia consensus development conference, Carlsbad, California, 2015. Br J Sports Med. 2015 Nov;49(22):1432-46.[Abstract][Full Text]
41. Jacob P, Dow C, Lasker SS, et al. Hyponatraemia in primary care. BMJ. 2019 May 9;365:l1774.[Abstract][Full Text]
42. Hillier TA, Abbott RD, Barrett EJ. Hyponatremia: evaluating the correction factor for hyperglycemia. Am J Med. 1999 Apr;106(4):399-403.[Abstract]
43. Nguyen MK, Kurtz I. Derivation of a new formula for calculating urinary electrolyte-free water clearance based on the Edelman equation. Am J Physiol Renal Physiol. 2005 Jan;288(1):F1-7.[Abstract][Full Text]
44. Lindner G, Schwarz C. Electrolyte-free water clearance versus modified electrolyte-free water clearance: do the results justify the effort? Nephron Physiol. 2012;120(1):p1-5.[Abstract]
45. Liamis G, Liberopoulos E, Barkas F, et al. Diabetes mellitus and electrolyte disorders. World J Clin Cases. 2014 Oct 16;2(10):488-96.[Abstract][Full Text]
46. Tandukar S, Sterns RH, Rondon-Berrios H. Osmotic demyelination syndrome following correction of hyponatremia by ≤10 mEq/L per day. Kidney360. 2021 Sep 30;2(9):1415-23.[Abstract][Full Text]
47. MacMillan TE, Cavalcanti RB. Outcomes in severe hyponatremia treated with and without desmopressin. Am J Med. 2018 Mar;131(3):317.e1-317.e10.[Abstract]
48. Baek SH, Jo YH, Ahn S, et al. Risk of overcorrection in rapid Intermittent bolus vs slow continuous infusion therapies of hypertonic saline for patients with symptomatic hyponatremia: the SALSA randomized clinical trial. JAMA Intern Med. 2021 Jan 1;181(1):81-92.[Abstract][Full Text]
49. Sterns RH. Disorders of plasma sodium - causes, consequences, and correction. N Engl J Med. 2015 Jan 1;372(1):55-65.[Abstract]
50. Nagler EV, Vanmassenhove J, van der Veer SN, et al. Diagnosis and treatment of hyponatremia: a systematic review of clinical practice guidelines and consensus statements. BMC Med. 2014 Dec 11;12:1.[Abstract][Full Text]
51. Buchkremer F, Segerer S, Bock A. Monitoring urine flow to prevent overcorrection of hyponatremia: derivation of a safe upper limit based on the Edelman equation. Am J Kidney Dis. 2019 Jan;73(1):143-5.[Abstract]
52. Dixon MB, Lien YH. Tolvaptan and its potential in the treatment of hyponatremia. Ther Clin Risk Manag. 2008 Dec;4(6):1149-55.[Abstract][Full Text]
53. Nagler EV, Haller MC, Van Biesen W, et al. Interventions for chronic non-hypovolaemic hypotonic hyponatraemia. Cochrane Database Syst Rev. 2018 Jun 28;(6):CD010965.[Abstract][Full Text]
54. Zhou Y, Yang W, Liu G, et al. Risks of vaptans in hypernatremia and serum sodium overcorrection: a systematic review and meta-analysis of randomised controlled trials. Int J Clin Pract. 2021 Jun;75(6):e13939.[Abstract]
55. Rondon-Berrios H, Tandukar S, Mor MK, et al. Urea for the treatment of hyponatremia. Clin J Am Soc Nephrol. 2018 Nov 7;13(11):1627-32.[Abstract]
56. Sterns RH, Silver SM, Hix JK. Urea for hyponatremia? Kidney Int. 2015 Feb;87(2):268-70.[Abstract][Full Text]
57. Hoorn EJ, Zietse R. Diagnosis and treatment of hyponatremia: compilation of the guidelines. J Am Soc Nephrol. 2017 May;28(5):1340-9.[Abstract][Full Text]
58. Chen Z, Jia Q, Liu C. Association of hyponatremia and risk of short- and long-term mortality in patients with stroke: a systematic review and meta-analysis. J Stroke Cerebrovasc Dis. 2019 Jun;28(6):1674-83.[Abstract]
59. Sun L, Hou Y, Xiao Q, et al. Association of serum sodium and risk of all-cause mortality in patients with chronic kidney disease: a meta-analysis and sysematic review. Sci Rep. 2017 Nov 21;7(1):15949.[Abstract][Full Text]
60. Renneboog B, Musch W, Vandemergel X, et al. Mild chronic hyponatremia is associated with falls, unsteadiness, and attention deficits. Am J Med. 2006 Jan;119(1):71.e1-8.[Abstract]
61. Verbalis JG, Barsony J, Sugimura Y, et al. Hyponatremia-induced osteoporosis. J Bone Miner Res. 2010 Mar;25(3):554-63.[Abstract][Full Text]
