Which investigations would be useful to help diagnose DI?
- Urine volume measurement (to assess for polyuria)
- Serum electrolytes (to measure serum sodium)
- Serum glucose (to exclude hyperglycaemia as a cause of polyuria)
- Urinary specific gravity (to exclude osmotic diuresis)
- Paired plasma and urinary osmolality (to demonstrate a high serum and low urine osmolality)