Like nearly all other life forms, humans require water for tissue hydration. Lack of hydration causes thirst, a desire to drink which is regulated by the hypothalamus in response to subtle changes in the body’s electrolyte levels and blood volume. A decline in total body water is called dehydration and will eventually lead to death by hypernatremia. Methods used in the management of dehydration include assisted drinking or oral rehydration therapy. An overconsumption of water can lead to water intoxication, which can dangerously dilute the concentration of salts in the body. Overhydration sometimes occurs among athletes and outdoor laborers, but it can also be a sign of disease or damage to the hypothalamus. A persistent desire to drink inordinate quantities of water is a psychological condition termed polydipsia. It is often accompanied by polyuria and may itself be a symptom of Diabetes mellitus or Diabetes insipidus.