The effects of dehydration on brain volume -- preliminary results

Int J Sports Med. Jul-Aug 2005;26(6):481-5. doi: 10.1055/s-2004-821318.


In adults the cranium is a rigid bony vault of fixed size and therefore the intra-cranial volume is a constant which equals the sum of the volume of the brain, the intra-cranial volume of CSF and the intra-cranial volume of blood. There can be marked changes in the volumes of these three intra-cranial compartments which may influence susceptibility to brain damage after head injury. This is the first study to investigate the relationship between dehydration and changes in the volume of the brain and the cerebral ventricles. Six healthy control subjects underwent magnetic resonance imaging of the brain before and after a period of exercise in an environmental chamber. The subjects lost between 2.1 % and 2.6 % of their body mass due to water loss through sweating. We found a correlation between the degree of dehydration and the change in ventricular volume (r=0.932, p=0.007). The changes in ventricular volume caused by dehydration were much larger than those seen in day-to-day fluctuations in a normally hydrated healthy control subject.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Adolescent
  • Adult
  • Body Composition
  • Brain / pathology*
  • Creatine / blood
  • Dehydration / etiology
  • Dehydration / metabolism
  • Dehydration / pathology*
  • Exercise*
  • Football
  • Hematocrit
  • Hemoglobins / analysis
  • Humans
  • Male
  • Organ Size
  • Osmolar Concentration
  • Plasma Volume
  • Potassium / blood
  • Sodium / blood
  • Urea / blood
  • Urine / chemistry


  • Hemoglobins
  • Urea
  • Sodium
  • Creatine
  • Potassium