If a diver surfaces with blood and mucous in their mask, what is the likely issue?

Surfacing with blood and mucous in the mask is commonly associated with sinus squeeze. This condition occurs when there is a pressure imbalance in the sinuses, typically caused by insufficient equalization during ascent or descent. As a diver descends, the pressure increases, and if the sinuses are not equalized properly, it can lead to pain and injury to the sinus tissues. When the diver ascends, the pressure decreases rapidly, and if the sinus cannot equalize properly, it may result in bleeding and mucous discharge as the delicate membranes become damaged.

This situation is particularly evident in divers experiencing sinus squeeze, as the signs, including blood and mucous, can become apparent during the ascent. The presence of these symptoms indicates the failure of the sinus passages to equalize properly, leading to the possible rupture of small blood vessels and inflammation.

Other options relate to different types of pressure-related injuries. Barotrauma generally refers to injuries caused by unequal pressure in various body areas, but it doesn't specifically focus on the sinus area. Ear squeeze involves pressure differences in the inner ear, leading to discomfort or injury in that area, and decompression sickness is related to nitrogen bubbles forming in the tissues after rapid ascents, rather than specific signs related to mucous