[Changes in electrolyte and water balance in old age].

The involutive restriction of renal function, of thirst, and loss of body fluid reduce the adaptability of the electrolyte- and fluid metabolism in the geriatric patient. The causes of hydromineral emergencies involving the elderly are discussed. It is explained how, in the geriatric patient, the rapid disturbance of fluid metabolism can frequently pose a more serious threat to life than the underlying pathology, and how awareness of this problem and its rapid resolution can often save the geriatric patient's life.