Primary polydipsia symptoms, such as delusions involving fluid intake or other unusual behaviours. Primary polydipsia may have physiological causes, such as autoimmune hepatitis. Since primary polydipsia is a diagnosis of exclusion, the diagnosis may be made for patients who have medically unexplained excessive thirst, and this is sometimes incorrectly referred to as "psychogenic" rather than "primary" polydipsia. As a diagnosis of exclusion, a diagnosis of primary polydipsia may be the result of elimination of the possibility of diseases causing similar signs and symptoms, such as diabetes insipidus. Diagnosis may be complicated by the fact that chronic and extreme compulsive drinking may impair
Polydipsia in birds has been experimentally induced in pigeons, budgerigars and ducks, by the administration of lithium chloride (LiCl). The polydipsic effect was greatest in budgerigars, a desert-dwelling species with a well-developed fluid retention system, and least in ducks, a species with an efficient sodium-secretion system. In waterfowl, polydipsia can be a symptom of duck virus enteritis. Polydipsia has also been listed as a symptom of many diseases, including In hens, lesions of the supraoptic hypothalamus of the brain can result in polydipsia. Polydipsia sometimes occurs under housing or experimental conditions which purportedly lead to stress or frustration. Growing parent stock of meat-type