Test	Considerations
Comprehensive metabolic panel	Hyperglycemia may suggest false low sodium (hypertonic hyponatremia) instead of true hypotonic hyponatremia Abnormal liver function test results may suggest liver dysfunction as a contributor Elevated creatinine or blood urea nitrogen helps determine volume status and may indicate a kidney-related etiology
Serum osmolality	Differentiates between true hypotonic hyponatremia and alternate etiologies
Urine screening (urine sodium, creatinine, osmolality)	Helps distinguish etiologies based on volume status