Urine osmolality

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Clinical indications:

• Determination of serum and urine osmolality can be useful in the assessment of electrolyte and acid-base disorders. 
• Comparison of serum and urine osmolalities can determine the status of renal water regulation in settings of severe electrolyte disturbances as might occur in diabetes insipidus or the syndrome of inappropriate anti-diuretic hormone. 
• Osmolality may also be performed as part of a water deprivation test (used in the diagnosis of diabetes insipidus) or where there is suspicion of ingestion of an osmotically active substance such as ethanol, methanol or ethylene glycol. 

 

Specimen type: 

• Urine

 

Sample type: 

• Random Urine

 

Turnaround time:

• Inpatient: 24 hours
• Outpatient: 24 hours
• GP: 24 hours

 

Reference interval:

300-900 mOsm/kg