Whether drowning occurs in a suicide attempt, by accident or in relation to an intentional act (such as pushing), the pathophysiology of drowning AT13387 a complicated process where different steps can take place: such as breath holding, CO2 accumulation and water aspiration  and . Depending on the drowning medium, fresh or salt water, a variety of physiological alterations appear such as bronchospasms, electrolyte changes. Another phenomenon is the surfactant deficiency where both fresh and – to a lesser degree – seawater, induces alveolar instability and permeability, resulting in pulmonary edema . Aspiration of seawater leads to an increase in the volume of fluid within the air spaces of the lungs . Additionally the hypertonic seawater pulls fluid from the circulation into the lungs . Hypotonic fresh water causes a massive absorption of water through the alveolar membrane, with an increase in blood volume and hemodilution within minutes. This hemodilution can be visible on CT images as a reduction in blood density . Seawater, on the other hand, causes a hypovolemia and hemoconcentration .