Case Report: An interesting case of a patient who presented with increasing thirst and polyuria in a district general hospital in the UK

A gentleman presented with polyuria and polydipsia to the Endocrine Clinic in late 2020. The patient was investigated extensively. Diabetes Mellitus was excluded, and the patient was investigated for Diabetes Insipidus (DI). The patient was passing more than 3L of urine/day. A Water deprivation Test (WDT) was done, and it suggested Partial Central Diabetes Insipidus (Partial Arginine Vasopressin Deficiency), which is a rare disorder. Various blood tests looking for the aetiologies such as Sarcoid, Germinoma, IgG4 Disease and Vasculitis were negative. MRI scan of the Pituitary carried out twice showed no abnormality. The patient’s distressing symptoms were alleviated with proper treatment (nasal Desmopressin). Thus, it is important to diagnose this treatable condition which is often confused with Primary Polydipsia. The patient has since then been clinically and biochemically well.