Considerations for the Prevention of DCS “Do’s” and “Dont’s”

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Disclaimer: the information presented here is not personal opinion but based on the latest scientific evidence on DCS. The phenomena of DCS are still not completely understood. Neither do we have “rock-solid” prevention strategies. Instead, the prevention strategies presented here are suggestions. There are always >5% of the diver population that are outliers, i.e. who will behave completely differently than 95% of all other divers. There is no test at this time that identifies those outliers.


Do: Numerous studies have shown that exercise and physical fitness decreases your risk of DCS! Pre-dive exercise (aerobic not weight training) between 2-24 hrs. before the dive is protective.

Do: Mild exercise (swimming, finning) during your decompression is protective against DCS.

Don’t: be a couch potato. Although exercising during the 24 hrs. is protective, there is strong evidence that regular aerobic exercise is protective by an independent mechanism.

Don’t: Remain motionless during your deco.

Do/Don’t: Exercise immediately (30-40 min) after diving. Not clear if it safe.

Do: Re-hydrate immediately after the dive. It is during the dive, where we lost a lot of our hydration and need to replenish!

Don’t: Aggressively hydrate before the dive. Overhydration puts a lot of strain on your heart and actually may put you at risk for developing pulmonary edema. Obviously, if you have a stomach bug and become dehydrated, you need to replenish until you get to euvolemia (normal body fluid volume) again. If you were binge drinking the night before, (another don’t, by the way), you need to replenish.

Don’t: Hit the bar and load up on alcoholic beverages after the dive. You need to re-hydrate your body first! Be responsible with your alcohol intake when diving! Too much alcohol will not only give you a hangover the next day, but will be dehydrating, as well. Your liver may not metabolize too much alcohol in time before jumping in the water the next day! You basically are diving while intoxicated!

Greasy Food
Don’t: Eat greasy, fat laden food just before the dive or in-between dives (as during your surface interval). Having fat globules cursing through your body while exposed to decompression stress is not a good idea.

Do: Eat foods rich in anti-oxidants such as dark, leafy vegetables, berries, etc. Consider taking 1000 mg Vitamin C with 400 IU Vitamin E 30 minutes before the dive. Breathing compressed air at depth (even 21%) increases the amount of free radicals from reactive oxygen species. Higher PO2’s will increase your free radical generation. Having too many free radicals is damaging to various systems in your body. Anti-oxidants will help eliminate free radicals. By the way, eating greasy foods will also increase free radicals.

Body Fat
Strive to decrease the amount of body fat you carry. Become leaner and meaner without loosing muscle mass. As one study summarized: “Younger, slimmer, or aerobically fitter divers are known to produce less bubbles compared to older, fatter, or poorly physically fit divers”.

We can’t do anything about getting older (in years), but we can keep our bodies “younger” with a healthier lifestyle!

Safe Diving!

Claudia L. Roussos MD
Diplomat Board of Anesthesiology
Member ADDHelium Dive Team
Last Update: 14 April 2013