Blood Coagulation Changes at High Altitude

Abstract

The current concepts of blood coagulation changes in the pathogenesis of acute mountain sickness (AMS), high altitude pulmonary oedema (HAPO), high altitude pulmonary hypertension (HAPH) and chronic mountain sickness(CMS) which afflict the inductees and residents at high altitude have been reviewed. Hypercoagulable state which is more marked during the first few days of exposure is countered by enhanced fibrinolytic activity and accelerated cell mediated immunity. Magnesium levels are increased in normal residents at high altitudes and may be responsible for enhancing fibrinolytic activity and accelerating immune responses. Magnesium levels are significantly reduced in HAPO patients. Judicious use of furosemide in lower dosage is still the mainstay of treatment of HAPO and AMS.