Which overexpansion injury can be characterized by chest pain, breathing difficulties, and cyanosis of the lips and nail beds?

The correct choice is indeed characterized by chest pain, breathing difficulties, and cyanosis of the lips and nail beds. This condition occurs when gas expands in the lungs and escapes into the mediastinum or pleural space due to changes in pressure, commonly associated with scuba diving or rapid ascents.

Mediastinal emphysema occurs when air leaks into the mediastinal space, which can lead to severe symptoms such as chest pain and difficulty breathing. Pneumothorax, which refers to air in the pleural cavity, can also develop as a result of overexpansion injuries. Both of these conditions can disrupt normal respiratory function and lead to inadequate oxygenation, causing cyanosis, or a bluish discoloration of the lips and nail beds, as the body struggles to obtain sufficient oxygen.

This choice addresses the specific symptoms and the underlying mechanisms tied to overexpansion injuries in the context of diving. Other options involve different bodily systems or symptoms that do not align with the signs described in the question.