Description
Why It’s Done:
This test is used to:
• Evaluate kidney function, especially the ability to concentrate urine.
• Help diagnose conditions such as:
o Dehydration or overhydration
o Syndrome of inappropriate antidiuretic hormone (SIADH)
o Diabetes insipidus
o Electrolyte imbalances
• Investigate causes of low or high blood sodium.
• Monitor patients receiving treatments that affect fluid balance or diuretics.
Preparation:
• No special preparation is needed for a random urine osmolality test.
• You may be advised to:
o Avoid excessive fluid intake before sample collection to prevent dilution.
o Inform your doctor about any medications you’re taking (especially diuretics, lithium, or ADH-related drugs), as these can affect results.
• A clean-catch urine sample is typically collected in a sterile container.
