What additional risk does ascending to altitude after a dive pose?

Ascending to altitude after a dive poses the additional risk of a reduction in atmospheric pressure. When a diver ascends to altitude, the surrounding atmospheric pressure decreases. This change can lead to decompression sickness, commonly known as "the bends," if a diver does not allow sufficient time for nitrogen to off-gas. During a dive, a diver's body absorbs nitrogen due to the increased pressure underwater; as the pressure decreases upon ascending to altitude, the nitrogen can form bubbles in the body if not allowed to safely release.

Ascension to altitude without proper precautions can increase the chances of these nitrogen bubbles forming, leading to potential health complications. Therefore, understanding atmospheric pressure's role when transitioning from underwater conditions to higher altitudes is crucial for a diver’s safety.