Clinical physiopathology of hypernatremia

BACKGROUND The maintenance of sodium levels at normal ranges has to be considered one of the most important and crucial physiological balance in order to preserve life. The increase of natremia determines the leakage of H₂O from the inside of cells and the consequent brain cells withering, that causes encephalopathy at different stages and in some cases it can even lead to death.
AIM OF THE STUDY The fundamentals of general physiopathology are analysed together with systems of compensation and brain adaptation in the three different aetiopathogenetic forms: primary increase of sodium (hypervolemic and haedematose form); missed introduction of pure water (mainly euvolemic form, with no aedema); loss of hypotonic fluids (hypovolemic form with dehydration). The three different clinical entities with their relative clinical approaches have been described.