Disorders of Water Balance: Hyponatremia

  • Alluru S. ReddiEmail author


Where Nae + and Ke + are total exchangeable quantities of these cations, and TBW is total body water. Therefore, hyponatremia can develop by an increase in total body water, a decrease in Na+ and K+ or a combination of both. Hyponatremia is a condition of water excess relative to Na+. In a normal individual, hyponatremia does not develop unless water intake is greater than renal excretion. A defect in renal water excretion in the presence of normal water intake is a prerequisite for the development of hyponatremia. This defect in water excretion is due to high circulating levels of antidiuretic hormone (ADH). With retention of water, hyponatremic patients are unable to lower their urine osmolality < 100 mOsm/kg H2O with the exception of those with psychogenic polydipsia and reset osmostat.


Water balance disorders Disorders of water balance Hyponatremia Total body water Antidiuretic hormone and water balance Urine osmolality 

Suggested Reading

  1. 2.
    Adroguè HJ, Madias NE. The challenge of hyponatremia. J Am Soc Nephrol. 2012;23:1140–8.PubMedCrossRefGoogle Scholar
  2. 8.
    Adroguè HJ, Madias NE. Hyponatremia. N Engl J Med. 2000;342:1581–9.PubMedCrossRefGoogle Scholar
  3. 6.
    Berl T. Impact of solute intake on urine flow and water excretion. J Am Soc Nephrol. 2008;19:1076–8.PubMedCrossRefGoogle Scholar
  4. 9.
    Furst H, Hallows KR, Post J, et al. The urine/plasma electrolyte ratio: a predictive guide to water restriction. Am J Med Sci. 2000;319:240–4.PubMedCrossRefGoogle Scholar
  5. 7.
    Lien Y-HH, Shapiro JI. Hyponatremia: clinical diagnosis and management. Am J Med. 2007;120:653–8.PubMedCrossRefGoogle Scholar
  6. 4.
    Maesaka JK, Imbriano LJ, Ali NM, et al. Is it cerebral or renal salt wasting. Kidney Int. 2009;76:934–8.PubMedCrossRefGoogle Scholar
  7. 5.
    Reddy P, Mooradian AD. Diagnosis and management of hyponatraemia in hospitalized patients. Int J Clin Pract. 2009;63:1494–508.PubMedCrossRefGoogle Scholar
  8. 3.
    Sterns RH, Hix JK, Silver S. Treating profound hyponatremia: a strategy for controlled correction. Am J Kidney Dis. 2010;56:774–9.PubMedCrossRefGoogle Scholar
  9. 1.
    Thurman JM, Berl T. Disorders of water metabolism. In: Mount DB, Sayegh MH, Singh AJ, editor. Core concepts in the disorders of fluid, electrolytes and acid-base balance. New York: Springer; 2013. pp 29–48.Google Scholar

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.Department of Medicine Division of Nephrology and HypertensionRutgers New Jersey Medical SchoolNewarkUSA

Personalised recommendations