Two mechanisms have been proposed as causes: syndrome of inappropriate anti-diuretic hormone and cerebral salt wasting. Physical examination and laboratory results can assist a clinician in ...

These diagrams show what happens when there is either too little or too much water in the blood.

The reabsorption of water back into the blood (at the medulla) is controlled by the anti-diuretic hormone (ADH). ADH is produced by the part of the brain that monitors water levels in the blood.

"Normally, our pituitary glands produce a hormone called anti-diuretic hormone (AVP) that sends a signal to our kidneys that regulates how much urine we produce," Kargi said. "AVP deficiency or ...