Diver sickness describes a cluster of physical and psychological symptoms that can occur during or after a scuba diving session. While often mild, these conditions can escalate quickly and ruin an otherwise perfect day on the water. Understanding the root causes, which range from environmental stressors to physiological reactions, is the first step in prevention.
Decompression Sickness: The Silent Threat
Decompression sickness (DCS), often called "the bends," remains the most serious medical concern for divers. This condition arises when dissolved gases, primarily nitrogen, form bubbles in the bloodstream and tissues as a diver ascends too quickly. The critical factor is the rate of pressure reduction, which dictates how safely the body can off-gas.
Recognizing the Symptoms
The presentation of DCS can vary widely, making vigilance essential. Joint pain, often described as a deep ache, is one of the most common indicators. More severe signs include skin rashes, extreme fatigue, difficulty breathing, and neurological issues such as numbness or confusion. Immediate recognition of these symptoms and initiation of oxygen administration is vital for a positive outcome.
Barotrauma: Equalization Failures
Barotrauma refers to injuries caused by the inability to equalize pressure in air spaces within the body. As a diver descends, the increasing water pressure compresses air spaces in the ears, sinuses, and mask. Failure to equalize effectively can lead to pain, ruptured eardrums, or sinus barotrauma, which can force a diver to end their dive prematurely.
Preventing Pressure-Related Injuries
Prevention relies heavily on proper technique and awareness. Divers should never hold their breath while ascending, as expanding air can cause lung overpressure injuries. Gentle and consistent equalization, performed frequently during descent, is the best defense. Avoiding diving with severe congestion is also a critical precaution against barotrauma.
Arterial Gas Embolism: A Rapid-Onset Emergency
Arterial Gas Embolism (AGE) is a rare but life-threatening emergency often linked to lung overpressure trauma. It occurs when a diver breathes in compressed air and holds their breath during ascent, causing the alveoli in the lungs to rupture. This allows air to enter the arterial bloodstream, potentially blocking blood flow to the brain or heart.
Key Distinctions from DCS
While both AGE and DCS are treated with hyperbaric oxygen therapy, their onset and mechanisms differ. AGE symptoms typically appear immediately upon surfacing or within minutes, whereas DCS symptoms may take hours to manifest. Rapid recognition and emergency oxygen are crucial for suspected AGE cases.
Environmental and Physical Factors
Beyond gas dynamics, several other factors contribute to diver sickness. Seasickness or motion sickness is common on boats, exacerbated by the rocking motion and the stress of preparing for a dive. Additionally, dehydration thickens the blood, making nitrogen elimination less efficient and increasing susceptibility to DCS.
Mitigating Non-Depth Risks
Divers can control many of these variables through preparation. Staying well-hydrated in the days leading up to a dive is one of the simplest and most effective strategies. Using stable ladders and boarding ladders carefully minimizes the physical shock to the system. Listening to your body and skipping a dive if you feel unwell are responsible decisions that prioritize long-term health.
