Symptoms of lung overexpansion injuries occur immediately, and can include difficulty breathing, chest pain, crackling under the skin, unconsciousness, or death. First aid must begin immediately while transportation to a medical facility is arranged.

First aid for lung injuries includes delivery of 100% oxygen and CPR if necessary. Reputable dive operators keep a supply of oxygen on their boats, and you can receive training for oxygen delivery by enrolling in a rescue diver or oxygen administrator course.

The victim will need treatment in a hyperbaric chamber as soon as possible. During this treatment, the victim is placed in a pressurized chamber to shrink the air bubbles, then slowly decompressed to allow the air to pass out of the body before it expands and interferes with respiration and circulation.