It is dangerous for a scuba diver to surface quickly due to a phenomenon called decompression sickness, also known as "the bends." When a diver is underwater, the increased pressure causes the body to absorb more nitrogen gas into the tissues and bloodstream. If the diver ascends too quickly, the reduction in pressure can cause the nitrogen to come out of solution and form bubbles in the body.
The rapid formation of these bubbles can lead to various symptoms, ranging from mild to severe, including joint pain, dizziness, fatigue, difficulty breathing, chest pain, neurological issues, and even death in extreme cases. These symptoms occur because the nitrogen bubbles can obstruct blood vessels, causing tissue damage and affecting the proper functioning of organs.
To prevent decompression sickness, divers must ascend slowly and perform decompression stops at certain depths to allow the excess nitrogen to be released gradually from the body. These stops provide a controlled and gradual decrease in pressure, allowing the nitrogen to safely come out of solution and be eliminated through the lungs without forming harmful bubbles.
Proper dive planning, following dive tables or dive computer algorithms, and adhering to safe ascent rates are crucial to avoiding decompression sickness and ensuring the safety of scuba divers.