A lot of people, whether they are divers or not, have heard of the “bends” or getting “bent”, but quite a few of them don’t really know what it means.
The “bends” is a colloquial expression that refers to a specific type of decompression sickness (DCS for short). As you are diving the nitrogen in the compressed air you are breathing builds up in your blood stream and other tissues due to the increased pressure you are under at depth. DCS is the result of these gasses not being properly released before you reach surface.
DCS is broken down into two types. Type I DCS is the expansion of these gasses in your joints, bones, muscles or other dense tissues and is commonly referred to as pain only DCS. This usually takes place within one to two hours of the end of the dive, but a small percentage of cases occur up to 48 hours after the dive. Type I DCS is the historical origin of the term the “bends” as the intense pain this process causes left its victims unable to straighten their limbs and often they just curl up in the fetal position. Type II DCS is the more serious of the two and results from the rapid formation and expansion of bubble in the blood or in the central nervous system. The symptoms of type II DCS such as intense headache, slurred speech, blurred vision, blotchy skin, and other neurological deficits almost always occur within 10 minutes of the end of a dive and can be fatal within minutes if not promptly treated in severe cases.
Fortunately it is fairly easy to avoid getting DCS. Following your schedule from the tables or following the limits your dive computer gives you and not ascending faster than 30 ft/min is the easiest method to avoid DCS and indeed leads to millions of safe dives a year. Staying hydrated, in reasonable physical condition, and not taking any medications including over the counter medications are also prudent and proven measures you can take to avoid the risk of suffering from DCS. If you have any further questions about DCS or its treatment feel free to drop in and ask our staff. Enjoy your next dive but remember to dive safe!