Unrelated to the more common diabetes mellitus, DI is a serious condition which occurs when the brain doesn’t produce enough antidiuretic hormone (ADH, also known as arginine vasopressin or AVP), called ‘cranial DI’, or the kidneys don’t respond to normal levels of ADH called ‘nephrogenic DI’. There are 2 other types – DI in pregnancy, ‘gestational DI’, and problems with thirst regulation, ‘dipsogenic DI’. There are many causes of all types of DI, including infections, certain medications, blood disorders and head injuries or tumours, but for some the cause is unknown or may be genetic. It can occur at any age, affecting 1 in 25,000. All types result in an inability to concentrate urine, so patients pass very large volumes of dilute urine.
The symptoms
These include excessive thirst and…
