Hyperbaric therapy works by applying higher ambient pressure to treat gas-related injuries, so the main aim is to shrink the nitrogen bubbles and improve their removal while protecting tissues. The increased pressure compresses existing bubbles (making them smaller and less obstructive), which helps restore blood flow and limits tissue injury. At the same time, the high-pressure, oxygen-rich environment increases the amount of inert gas that can dissolve in the blood and tissues and then be washed out as the diver breathes normal air or oxygen, speeding inert gas elimination. This combination reduces ongoing damage from bubbles and ischemia and accelerates recovery, rather than trying to instantly eradicate every bubble or addressing other non-therapeutic actions like sedation or surgery.

When a diver ascends, dissolved gases come out of solution as bubbles. The gas most responsible is nitrogen because air is mostly nitrogen, and under pressure nitrogen dissolves in blood and tissues. As you rise and ambient pressure falls, that dissolved nitrogen supersaturates and forms gas bubbles, causing decompression sickness. Oxygen is metabolized and exhaled, and carbon dioxide is continually off-gassed, so they don’t form the characteristic inert-gas bubbles seen in DCS. Helium can be involved only in very deep dives using special gas mixes, but for typical situations the primary bubble-forming inert gas is nitrogen.

AGE, or arterial gas embolism, is best described as an event where a rapid ascent or lung barotrauma forces air into the arterial circulation, sending bubbles to the brain and spinal cord. This produces abrupt neurologic signs—such as sudden confusion, dizziness, loss of consciousness, or focal deficits—immediately after surfacing or after a lung injury. That quick, neurological-onset pattern after a dive makes this description the most accurate. Chronic cough isn’t typical of AGE, which is an acute event, and AGE is not limited to deep-sea divers—any diver who ascends rapidly or sustains pulmonary barotrauma can be affected. While AGE can overlap with decompression sickness, it is not indistinguishable from it; AGE has a distinctive, sudden neurologic presentation due to arterial bubbles, whereas DCS often presents with joint/muscle pains and skin symptoms that develop more gradually.

Neurological involvement from Decompression Sickness Type 2 happens when nitrogen bubbles affect the nervous system after surfacing. Tingling is a classic sign because it reflects abnormal sensory nerve activity—paresthesias—that can occur when bubbles irritate or disrupt nerves in the brain, spinal cord, or peripheral nerves. This type of symptom points to nerve or CNS involvement, which is the hallmark of Type 2. Hearing loss can occur with inner ear involvement but is not a universal neurological symptom and is more about vestibular or auditory nerve irritation. Coughing signals pulmonary involvement, not the nervous system. Marbling is a skin sign from cutaneous involvement, not a nervous-system issue. So tingling best exemplifies the neurological effects of Type 2 DCS after surfacing. If this sign appears, treat as suspected DCS and seek urgent hyperbaric care.