What condition can arise from free ascent without proper procedures?

Decompression sickness, commonly referred to as "the bends," can occur if a diver ascends too quickly without following proper ascent procedures, such as safety stops. During a free ascent, the diver’s body experiences a rapid decrease in surrounding pressure. If this ascent is too fast, dissolved gases (primarily nitrogen) in the body can form bubbles, leading to a variety of symptoms depending on the severity and location of the bubbles in the body. These can range from joint pain to more severe conditions affecting the nervous system or lungs.

The key to preventing decompression sickness lies in adhering to ascent protocols that help allow gases to safely vent from the body. This is why proper ascent procedures, including controlled ascent rates and safety stops, are crucial for divers, particularly when using enriched air nitrox, which can have different saturation levels in the body compared to air.