Which overexpansion injury is characterized by chest pain and cyanosis of the lips?

The overexpansion injury characterized by chest pain and cyanosis of the lips is associated with both pneumothorax and mediastinal emphysema.

When a diver ascends too quickly or does not manage air expansion adequately, gas can become trapped in the chest cavity or tissues. In the case of pneumothorax, air can leak into the pleural space, leading to increased pressure, which causes chest pain and can also result in cyanosis due to reduced oxygenation as the lungs struggle to expand properly.

Mediastinal emphysema occurs when air becomes trapped in the mediastinal space, causing similar symptoms. Chest pain and cyanosis of the lips may present due to the associated difficulty in breathing and reduced oxygen levels in the blood.

Both conditions arise from overexpansion principles and need immediate medical attention, emphasizing the importance of proper ascent procedures and knowledge of these potential injuries in diving.