text: Excessive losses of water from the urinary tract – which may be caused by glycosuria, or other osmotic diuretics (e.g., mannitol) – leads to a combination of sodium and free water losses.
  Water losses associated with extreme sweating.
  Severe watery diarrhea (osmotic diarrhea results in hypotonic (dilute) watery diarrhea resulting in significant loss of free water and a higher concentration of sodium in the blood; this type of water loss can also be seen with viral gastroenteritis).
  Normal volume
  In those with normal volume or euvolemia:
  Excessive excretion of water from the kidneys caused by diabetes insipidus, which involves either inadequate release of antidiuretic hormone from the pituitary gland, or impaired responsiveness of the kidneys to it.
  High volume
  In those with high volume or hypervolemia:
  Intake of a hypertonic fluid (a fluid with a higher concentration of solutes than the remainder of the body) with restricted free water intake.  This is relatively uncommon, though it can occur after a vigorous resuscitation where a patient receives a large volume of a concentrated sodium bicarbonate solution. Ingesting seawater also causes hypernatremia because seawater is hypertonic and free water is not available. There are several recorded cases of forced ingestion of concentrated salt solution in exorcism rituals leading to death.
  Mineralcorticoid excess due to a disease state such as Conn's syndrome usually does not lead to hypernatremia unless free water intake is restricted.