Which condition could result from diving at excessive depths without proper training?

Diving at excessive depths without proper training can lead to decompression sickness, commonly known as "the bends." This condition occurs when a diver ascends too quickly after being at significant depths. Under increased pressure, nitrogen from the breathing gas dissolves into the body tissues. If a diver ascends too rapidly, the decrease in pressure causes this dissolved nitrogen to form bubbles in the bloodstream and tissues, leading to various symptoms such as joint pain, dizziness, and in severe cases, can result in paralysis or death.

Understanding the dynamics of pressure changes in diving is crucial, and adhering to safe ascent rates is a key training component to avoid this hazardous condition. Training also emphasizes the use of proper gas mixtures and no-decompression limits, which are essential for safe deep diving practices. While other choices mention important aspects of diving, such as oxygen toxicity and drowning, the specific risk related to improper ascent from extreme depths is directly linked to decompression sickness.