<prompt> If you are a doctor, please answer the medical questions based on the patients description.My husband has a history of stroke and mini strokes. Last plane flight was 2 years. Ago, had to fly home from Florida with oxygen tank after being hospitalized for 12 days, also he is on dialysis 3 days a week. Is it safe to fly for 6 hours? E mail is YYYYYY . Thank you.  <response>: Hello! Thank you for asking on Chat Doctor! I understand your concern and would like to explain that the risk of pulmonary embolism or a brain stroke is high from the coagulation changes induced by the renal failure. Staying in sitting position for 6 hours, taking into consideration the atmospheric pressure changes, would face him with a higher risk for acute complications. If this flight is extremely necessary, I recommend performing some tests like: - resting ECG-complete blood count- coagulation tests INR, PT- kidney and liver function tests-fasting glucose-blood electrolytes, etc. An injection of enoxaparine or fraxiparine before the flight may be helpful in preventing possible embolic or just aspirin if no contraindications. Hope to have been helpful! Best wishes, 