Fluid deprivation test Fluid deprivation test A fluid or water deprivation test is a medical test which can be used to determine whether the patient has diabetes insipidus as opposed to other causes of polydipsia (a condition of excessive thirst that causes an excessive intake of water). The patient is required, for a prolonged period, to forgo intake of water completely, to determine the cause of the thirst. This test measures changes in body weight, urine output, and urine composition when fluids are withheld. Sometimes measuring blood levels of ADH (a synonym for vasopressin) during this test is also necessary. If there is
Primary polydipsia attention and motor speed. Other areas with volume reductions (both white and grey matter) include: Signs and symptoms of psychogenic polydipsia include: The most common presenting symptom is tonic-clonic seizure, found in 80% of patients. Psychogenic polydipsia should be considered a life-threatening condition, since it has been known to cause severe hyponatraemia, leading to cardiac arrest, coma and cerebral oedema. It can also cause central pontine myelinolysis. Treatment for psychogenic polydipsia depends on severity and may involve behavioural and pharmacological modalities. If the patient presents with acute hyponatraemia (overhydration) caused by psychogenic polydipsia, treatment usually involves administration of intravenous hypertonic