Which physical condition might affect a diver’s ability to equalize?

Congestion or sinus issues can significantly impact a diver's ability to equalize pressure in their ears and sinuses during descents. Equalization is the process of adjusting the pressure in the middle ear to match the surrounding water pressure, typically achieved through techniques such as the Valsalva maneuver. When a diver has congestion or sinus problems, the Eustachian tubes, which connect the middle ear to the back of the throat, may become blocked or inflamed, making it difficult to equalize pressure effectively. This obstruction can lead to discomfort, pain, and even injuries such as barotrauma, where tissues in the ear or sinuses are damaged due to pressure differences.

Overall, understanding the effects of congestion or sinus issues is crucial for divers, as it directly relates to their safety and comfort while diving, as proper equalization is essential to avoid complications associated with pressure changes underwater.