Hi there. The various possible causes
in your sister are, epilepsy or exposure to heat stroke or hypothermia, hypo or hyperglycemia, uremia or renal failure, trauma or head injury, stroke, psychosis etc. speak with your sister’s intensivist who would be able to tell more about the exact cause of coma in her, if it has been diagnosed. The hypotension could be due to vasomotor collapse or the centres in brain stem getting affected or circulatory shock or septicemia. All the best.