[Typical pathology during the free immersion of a man under water].

The free immersion of a man under the water is accompanied by the threat of specific disorders which could cause the drowning. The article examines the causes, conditions and mechanisms of two most frequent pathological states, i.e. the compression of thorax and loss consciousness caused by CO2 action and hypoxia. The symptoms of these states, as well as prophylactic measures and first aid recommendations are enclosed.