Urine Osmolality Test Price in Rasulgarh

Test Description

Urine osmolality measures the concentration of osmotically active particles in urine and reflects the kidney's ability to concentrate or dilute urine — a fundamental tubular function controlled by ADH (antidiuretic hormone/vasopressin). Normal urine osmolality ranges from 50 to 1,400 mOsm/kg water, depending on water intake and hydration status. A morning urine osmolality >800 mOsm/kg indicates good concentrating ability. Urine osmolality is used to: Evaluate polyuria: urine osmolality <150 mOsm/kg during polyuria (>3L/day) indicates diabetes insipidus (central or nephrogenic) or primary polydipsia; >600 mOsm/kg suggests osmotic diuresis (glucose, urea). Assess SIADH (syndrome of inappropriate ADH): inappropriately elevated urine osmolality (>100 mOsm/kg) with hyponatremia and low serum osmolality (<275 mOsm/kg). Evaluate hyponatremia: urine osmolality is a key branching point — dilute urine (<<100 mOsm/kg) suggests excess water intake (psychogenic polydipsia, iatrogenic); concentrated urine suggests appropriate (hypovolemia, hypothyroidism, adrenal insufficiency) or inappropriate (SIADH) ADH. Water deprivation test (followed by desmopressin) differentiates central from nephrogenic DI and primary polydipsia.