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"How dangerous is decompression sickness?"

ZocdocAnswersHow dangerous is decompression sickness?


I'm 29 and have scuba dived for four years. I've never had decompression sickness but I've heard horror stories. How dangerous is it? I try to be as carful as possible when coming up.


Scuba diving, while enjoyable, does carry the risk of decompression sickness, also known as "the bends." It is a serious, and potentially lethal disease, but treatable if diagnosed early. When the body is at high pressures, nitrogen from the atmosphere dissolves into the tissues. The amount of extra nitrogen dissolved in the body's tissues is determined by the depth (pressure) to which you dive and the amount of time you spend underwater. When you ascend after a dive, the extra nitrogen is released from your tissues and back into the blood. If you ascend slowly enough, your lungs can remove this extra gas by exhaling it. If you ascend too quickly, or have too much nitrogen dissolved in your tissues, it will form bubbles in your blood which produce symptoms of the bends. The symptoms of the bends are varied, but most often include joint, arm, and leg pain. More serious symptoms include dizziness and difficulty speaking or walking. Serious cases of the bends can result in coma or death. The chances of these symptoms occurring is reduced by diving for shorter periods of time at shallower depths (resulting in less nitrogen dissolving into the tissues) as well as by ascending more slowly (allowing the lungs more time to remove the gas). These symptoms often occur within the first hour after a dive, but at least half of the cases of the bends will occur an hour or more after resurfacing, and can occur many hours later. You should always dive with an experienced instructor, and make a dive plan that minimizes the risk of the bends by allowing intervals at shallow depths or at the surface. Before you dive, make sure you know where the nearest dive chamber is - this is a chamber which generates very high pressures, causing the gas to dissolve back into your tissues rather than forming bubbles. Also, if you notice severe symptoms of the bends, seek medical help immediately.

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