plasma ADH in response to infusion of hypertonic saline
Last reviewed 01/2018
This distinguishes cranial diabetes insipidus from primary polydipsia and nephrogenic diabetes insipidus:
- CDI patients have low plasma ADH
- NDI and PP patients show normal levels of plasma ADH
NDI patients may be distinguished by their high plasma ADH relative to urine osmolarity after a period of dehydration.