Adipsia

Adipsia is a syndrome characterized by an absence of the sensation of thirst. It involves an increased osmolality or concentration of solute in the urine, which stimulates secretion of antidiuretic hormone (ADH) from the hypothalamus to the kidneys. This causes the patient to retain water and ultimately become unable to feel thirst. Due to its rarity, the disorder has not been the subject of many research studies. Adipsia has been seen as a symptom of conditions such as Diabetes insipidus and hypernatremia, as the result of abnormalities in the hypothalamus, pituitary and corpus callosum, as well as following pituitary/hypothalamic surgery. It is possible for hypothalamic dysfunction, which may result in adipsia, to be present without physical lesions in the hypothalamus, although there are only four reported cases of this. There are also some cases of patients experiencing adipsia due to a psychiatric disease. In these rare psychogenic cases, the patients have normal levels of urine osmolality as well as typical ADH activity.