Pulmonary physiology is significantly altered during underwater exposure, as immersion of the body and increased ambient pressure elicit profound effects on both the cardiovascular and respiratory systems. Thoracic blood pooling, increased breathing gas pressures, and variations in gas volumes alongside ambient pressure changes put the heart and lungs under stress. Normal physiologic function and fitness of the cardiovascular and respiratory systems are prerequisites to safely cope with the challenges of the underwater environment when freediving, or diving with underwater breathing apparatus. Few physicians are trained to understand the physiology and medicine of diving and how to recognize or manage diving injuries. This article provides an overview of the physiologic challenges to the respiratory system during diving, with or without breathing apparatus, and outlines possible health risks and hazards unique to the underwater environment. The underlying pathologic mechanisms of dive-related injuries are reviewed, with an emphasis on pulmonary physiology and pathophysiology.

在水下暴露期间，肺部生理机能会发生显着改变，因为身体的浸泡和环境压力的增加会对心血管和呼吸系统产生深远的影响。胸部血液淤积、呼吸气体压力增加、气体体积变化以及环境压力变化使心脏和肺部承受压力。心血管和呼吸系统的正常生理功能和健康是自由潜水或使用水下呼吸器潜水时安全应对水下环境挑战的先决条件。很少有医生接受过了解潜水生理学和医学以及如何识别或处理潜水损伤的培训。本文概述了潜水过程中呼吸系统面临的生理挑战（无论是否使用呼吸器），并概述了水下环境特有的可能的健康风险和危害。回顾了潜水相关损伤的潜在病理机制，重点是肺生理学和病理生理学。