Avoid decompression illness by taking a conservative approach to diving. Decompression illness, also refered to as Caisson's Disease or the bends, is a painful and potentially lethal illness and can be broken down into two categories. The first, decompression sickness (DCS), involves a rapid change in body pressure which causes excess nitrogen bubbles to form inside the blood and tissues. The second, and more serious, is an arterial gas embolism (AGE), which creates a similar situation to that of decompression sickness, but affects lung circulation and potentially small blood vessel flow. DCS symptoms can include joint and muscle pain, vertigo and paralysis while AGE can cause blurred vision, convulsions, unconsciousness, inability to breath and death. Avoid these dangerous situations by not pushing decompression limits whether using computers or dive tables, continuously breathing throughout the entire dive and ascending slowly with an appropriate decompression stop.
Understand your limits and avoid nitrogen narcosis. Largely associated with diving at depth, the martini effect, as it is sometimes called, occurs when gas pressure increases as a diver descends. The deeper you go, the more nitrogen is dissolved via increased pressure, which is then released into the blood. Efffects of nitrogen narcosis essentially slows the nervous system down, which in turn negatively affects judgement. This, obviously, has potentially deadly consequences. For example, a diver feeling the buzz of increased nitrogen is likely to be negligent in monitoring oxygen consumption. Additionally, though there are prescribed limits as to dangerous levels of nitrogen, everyone is different. Just like with alcohol, some people have no tolerance and others can handle more. Avoid diving at depth and the chances of nitrogen narcosis are diminished a great deal. Most importantly, when diving deeper than normal, know the sypmtoms of nitrogen narcosis so as it begins to occur you can ascend. Command awareness when you dive and stay safe.
Equalize as you descend during a dive and avoid barotrauma. Barotrauma is a common diving injury that occurs through a difference in pressure between an air space inside the body, usually the middle ear and surrounding fluid. Barotrauma can also affect the lungs, sinuses, eyes and even teeth. Lung barotrauma is a particularly dangerous version though it can largely be avoided by simply breathing continuously during every ascent. As for middle ear barotrauma, the main technique to avoid this painful injury is through equalization. Equalization involves one of several, simple techniques that a diver can use during descent. The most common is the valsalva maneuver, where the nose is pinched and the ears are cleared by gently forcing air into them. Even easier, divers can thurst their chins outward or swallow and this often will equalize the passages. Further precautions can be taken by never diving when you are congested.