Volume depletion versus dehydration: how understanding the difference can guide therapy

Am J Kidney Dis. 2011 Aug;58(2):302-9. doi: 10.1053/j.ajkd.2011.02.395. Epub 2011 Jun 25.


Although often used interchangeably, dehydration and volume depletion are not synonyms. Dehydration refers to loss of total-body water, producing hypertonicity, which now is the preferred term in lieu of dehydration, whereas volume depletion refers to a deficit in extracellular fluid volume. In particular, hypertonicity implies intracellular volume contraction, whereas volume depletion implies blood volume contraction. Using a case of hyperglycemic hypertonic nonketosis as an example, we examine the changing composition of body fluid spaces to explore the distinction between dehydration and hypertonicity from volume depletion.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Dehydration* / diagnosis
  • Dehydration* / physiopathology
  • Dehydration* / therapy
  • Extracellular Fluid*
  • Fluid Therapy
  • Humans
  • Male
  • Terminology as Topic