As a physician who travels quite a lot, I spend a lot of time on planes listening for that dreaded “Is there a doctor on board?” announcement. I’ve been 1 only once – for a woman who had merely fainted. But the accident made me quite curious about how 2 this kind of thing happens I wondered what I would do if confronted with a real midair medical emergency - without access 3 a hospital staff and the usual emergency equipment. So when the New England Journal of Medicine last week 4 a study about in flight medical events , I read it with interest. The study estimated that there are a(n) 5 of 30 in-flight medical emergencies on U.S. flights every day. Most of them are not serious ;fainting and dizziness are the most frequent complaints. 6 13% of them –roughly four a day – are serious enough to require a pilot to change course. The most common of the serious emergencies 7 heart trouble. strokes, and difficulty breathing. Let’s face it: plane rides are stressful. For starters, cabin pressures at high altitudes are set at roughly 8 they would be if you lived at 5,000 to 8,000 feet above sea level. Most people can tolerate these pressures pretty easily , but passengers with heart disease 9 xperience chest pains as result of the reduced amount of oxygen flowing through their blood. Another common in-flight problem is deep venous thrombosis – the so-called economy class syndrome ( 综合症 ). 10 appens, don’t panic. Things are getting better on the in-flight-emergency front. Thanks to more recent legislation, flights with at least one attendant are starting to install emergency medical kits to treat heart attacks.