Diabetes insipidus (DI) is a rare disease that, like the more familiar diabetes mellitus, causes frequent urination. Interestingly, the “insipidus” in its name means “without taste,” which refers to the flavor of the urine associated with DI. “Mellitus,” which means “honey,” also describes the taste of the urine associated with that condition, which is (so we are told) sweet.
According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) website, DI is completely unrelated to diabetes mellitus. Nevertheless, the two diseases can have similar signs and symptoms. The excessive thirst and excessive urination that characterize both conditions can disrupt sleep and cause bedwetting. Dehydration can be a problem for people with DI. Children with DI may be irritable or listless and may have fever, vomiting, or diarrhea.
According to the NIDDK diabetes insipidus site, however, DI is rarely so severe that it endangers a person’s health. In that respect, it is very different from diabetes mellitus. In fact, milder forms of DI can be managed by drinking enough water, usually between 2 and 2.5 liters a day.
Because the symptoms of DI can closely resemble those of DM, healthcare providers must conduct tests to differentiate the two. It’s also necessary to diagnose which kind of DI a patient has. For example, one form of DI stems from damage to the pituitary gland, while another results when the kidneys are unable to respond to the production of antidiuretic hormone. Diagnosis is derived from tests, including urinalysis and a fluid deprivation test.
Source: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Note: The above website lists many resources for more information on DI.