How would you know if you have diabetes inspidus?

Worst Thirst Ever: People with diabetes insipidus feel horribly thirsty and pee a lot. Talk with your doc about tests to do [urine tests, MRI of pituitary, blood tests to check out other illnesses too].

Excessive urination: It is a very rare disease manifested by frequent urination and increased thirst. Typically more than 3 litres urine output/day and freqeunt urination at night

Testing: This can be verified UNDER SUPERVISION with a water withholding test. It compares urine concentration at several points while fluids are withheld to see if the kidneys can adapt and concentrate the urine (withhold water). It can be dangerous to try alone!! It is suggested when people drink copious amounts day & night. They frequently cannot drive an hour or two without drinking.