What tests can be done to diagnose diabetes insipidus? Just vasopressin?

Dehydration test. The dehydration test is used to diagnose diabetes insipidus. This test is typically performed at an endocrinology office. It involves not drinking any liquids for 12 hours and then labwork is done in the morning and six hours later.
Water deprivation . The classic diagnostic test first is a first morning urine sample for osm after not drinking and if greater than 300 excludes the diagnosis. Water deprivation in the hospital stop intake and check serum/urine osm every 2 h. If serum sodium rises greater than145 wihtout rise in urine osm the diagnosis is made. Vasopressin is given if the urine osm increases it is central di if not nephrogenic di.

Related Questions

During fluid deprivation test, the ADH (vasopressin) level dropped down to 1/3 of pre test level and below reference values. Is that a sign of diabetes insipidus?

Not necessarily. The most important thing to be following in a water deprivation test is the urine and serum osmolality. If the serum osmolality rises above normal, but the urine osmolality does not rise significantly, you have diabetes insipidus. Measuring ADH (vasopressin) levels can be unreliable. Read more...

Doc wants 2 do anti diuretic hormone (adh) test for diabetes insipidus. Thought u had 2 b deprived of fluid during ADH (vasopressin) test...Or is that necessary?

Yes. There is a test called water deprivation test which is the gold standard for testing but pt's have to be monitored closely. Therefore, sometimes we may give a trial of ADH (vasopressin) as a pill to see if the symptoms resolve after it has been verified pt's are making >3l of urine a day. Read more...