We present 87-year-old woman with moderate hypovolemia, severe hypernatremia (serum sodium 184 mmol/L) and hyperosmolarity (serum osmotic pressure 416 mOsm/L), due to reduced fluid intake and diuretic use, accompanied by acute kidney injury (pre-renal). However, the patient had very mild symptoms upon her admission (communication disorders, drowsiness). She was successfully treated in a common nursing ward, with careful assessment of the fluid status, as well as with careful restoration of her deficits (mainly water and much less sodium). Reference is made to the causes, frequency, clinical picture and outcome of these patients, as well as review of the literature.