What is the largest contributing factor to decompression sickness (DCS)?

The largest contributing factor to decompression sickness (DCS) is rapid ascent. When a diver ascends too quickly, the pressure around them decreases rapidly, which can result in nitrogen coming out of solution in the body tissues and blood. This can lead to the formation of bubbles, causing various symptoms associated with DCS.

Overexertion, dehydration, and alcohol consumption are all factors that can impact a diver's overall safety and well-being but do not directly cause DCS in the way that rapid ascent does. For example, while dehydration can impair a diver's physical performance and increase the risk of other diving-related issues, it does not inherently cause nitrogen bubbles to form as a result of pressure changes. Similarly, excessive alcohol consumption can lead to impaired judgment and reaction times but does not contribute to the mechanics of how DCS occurs during ascent.

Understanding the significance of maintaining a controlled ascent rate is crucial for divers to minimize the risks associated with decompression sickness. Proper training and adherence to ascent protocols help ensure that nitrogen is safely expelled from the body.