Adam surfaces from a cold dive feeling pressure behind his eyes, and reporting bloody water in his mask, but no other signs or symptoms. As team leader, you should suspect:

The situation described suggests that Adam is experiencing symptoms consistent with sinus squeeze, also known as barotrauma of the sinuses. When divers descend, the pressure increases, and the air-filled spaces in the body, such as the sinuses, must equalize to the surrounding water pressure. If a diver fails to equalize effectively, a pressure difference can develop, leading to discomfort, and in some cases, bleeding.

The presence of pressure behind the eyes indicates that there may be trapped air or a significant pressure differential in the sinus cavities. Additionally, the observation of bloody water in the mask could be due to bleeding from the nasal passages that may occur when the sinuses are injured or have ruptured from this pressure imbalance.

In contrast, decompression sickness primarily involves nitrogen bubbles forming in body tissues and does not typically present with sinus-related symptoms. Subcutaneous emphysema involves air escaping into subcutaneous tissue, which is not indicated by the symptoms described. An air embolism occurs when air enters the bloodstream, typically resulting from rapid ascents, and is characterized by a different set of symptoms, such as difficulty breathing, confusion, and potentially loss of consciousness.

Thus, the symptoms Adam is experiencing align most closely with sinus squeeze, leading to the conclusion