Primary polydipsia is also called dipsogenic diabetes insipidus or psychogenic polydipsia.
It can cause excretion of large volumes of dilute urine. Primary polydipsia is NOT a problem with ADH production or lack of response to ADH.
The underlying cause is an intake of excessive quantities of fluids (usually more than 12 liters/day). Ingestion of massive amounts of free water for a prolonged period of time alone can damage the kidneys and suppress ADH, making the body unable to concentrate urine.
Primary polydipsia may result from abnormal high thirst caused by damage to the thirst-regulating center in the hypothalamus. It has also been linked to mental disorders.