Causing trouble

摘要

One of life's quietly satisfying moments is boarding a long-haul flight and turning left. Although air travel has lost much of its glamour, flying first or business class is still a relief to the senses, compared with the rigours of economy further aft. The space and relative quiet at the front of the plane certainly make flying a more pleasant experience, but do they make it any safer? At issue is travel-related deep-vein thrombosis (DVT), otherwise known as economy-class syndrome. DVT describes the formation of clots known as thrombi in the blood vessels of various parts of the body, such as the lower leg. Clotting is a normal response to injury, and the body is continuously forming and removing clots that cause no obvious harm. Abnormal formation of clots, however, can lead to cramps, pain and swelling in the tissue affected. Far more serious is the possibility that the clot, or a piece of it, splits off and starts racing round the circulatory system. If this breakaway clot, called an embolus, gets stuck in a delicate part of the body, such as the lungs, it can kill.