Most scuba diving injuries are caused by which factor?

• A. Too rapid of a descent.
• B. Alcohol consumption.
• C. Cold water temperature.
• D. Too rapid of an ascent.

Answer: (D)

Rising too quickly during ascent drives the main injury mechanism in scuba diving: decompression sickness from inert nitrogen coming out of solution too fast. Under pressure at depth, nitrogen dissolves in tissues and the bloodstream. If you ascend rapidly, ambient pressure drops quickly and the dissolved nitrogen forms bubbles. These bubbles can block blood vessels and damage tissues, leading to joint pain, dizziness, weakness, or more serious neurological or cardiopulmonary problems, and in some cases can cause a gas embolism. Taking a slow, controlled ascent gives off-gassing time and safety stops to allow nitrogen to leave the body gradually, preventing these injuries. The other factors listed—descent speed, alcohol use, and cold water—can influence risk in other ways, but they don’t account for the majority of injuries as directly as an excessively rapid ascent does.