You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Earliest symptom of acute mountain sickness is and explain in detail?
The low paial pressure of oxygen at high altitude causes aeriolar dilatation and if cerebral autoregulation does not compensate, there is an increase in capillary pressure that ors increased transudation of fluid into brain tissue.Ref: Ganong's Review of Medical Physiology Kim E Barrett, Susan M Barman, Scott Boitano, Heddwen L Brooks 23rd edition page no - 619