Polyuria (Increased Urination): Test and Diagnosis

Laboratory parameters of the 1st order – obligatory laboratory tests.

  • Small blood count
  • Urine status (rapid test for: pH, leukocytes, nitrite, protein, glucose, ketone, urobilinogen, bilirubin, blood), sediment if necessary.
  • Urine volume
  • Electrolytes – calcium, potassium
  • Fasting glucose (fasting blood sugar)
  • Thirst test (two-step test) – diagnostic test designed to rule out diabetes insipidus.
  • Blood/urine osmolarity or blood/urine osmolality – to distinguish between osmotic and non-osmotic polyuria [normal finding: 600-900 mosmol].
  • ADH (antidiuretic hormone)
  • Renal parameters – urea, creatinine, cystatin C or creatinine clearance, as appropriate.