Altitude Sickness, Mount Everest

Marchbanks Measurement Systems is contributing to a project of some particular importance involving mountain sickness.

The clinical features of mild to moderate acute mountain sickness (AMS) include headache, nausea and vomiting which may progress to the more serious malignant form with ataxia, confusion and death.

Raised intracranial pressure and cerebral oedema secondary to hypoxia are central themes in the suggested mechanisms of AMS.


  • Raised intracranial pressure has been noted in severe forms of acute mountain sickness and high altitude cerebral oedema, but the role of intracranial pressure in the pathogenesis of mild to moderate acute mountain sickness is unknown.
  • Serial measurements of intracranial pressure were made indirectly by assessing changes in tympanic membrane displacement in 24 healthy subjects on rapid ascent to 5200m.
  • Acute hypoxia at 3440m was associated with a rise in intracranial pressure, but no difference was found in pressure changes at 4120 or 5200m in subjects with or without symptoms of acute mountain sickness.
  • Raised intracranial pressure, though temporarily associated with acute hypoxia, is not a feature of acute mountain sickness with mild or moderate symptoms.

Abstract from: Wright, AD, Imray, CHE, Morrissey, MSC, Marchbanks, RJ, Bradwell, AR, (1995). Intracranial pressure at high altitude and acute mountain sickness. Clin Sci. 89:201-204.

Further research
Use of the MMS CCFP Analyser to investigate changes in intracranial pressure fluid dynamics with acute mountain sickness.