Urine Sodium and Potassium 24-Hour Quantitative Collection with Differential Measurement
This test measures the amount of sodium and potassium in your urine over 24 hours, along with a breakdown of urine composition to help assess kidney function and fluid balance.
["Helps track how well your kidneys filter electrolytes and manage fluid levels over a full day’s output."]
Key facts at a glance
- LOINC
- 101734-2
- Short code
- Na Urate cry 24h EngDiff Ur
- Synonyms
- Na Urate cry 24h EngDiff Ur
- Category
- electrolyte
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 3.5
- Ref high
- 7.2
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your doctor may order this test to evaluate kidney function, detect electrolyte imbalances, or monitor conditions like hypertension, heart failure, or kidney disease. It also helps assess how well you’re retaining or losing sodium and potassium, which are vital for nerve and muscle function.
What to Expect Before the Test
You’ll collect all your urine for 24 hours, starting after midnight on one day and ending just after midnight the next. Drink normal fluids unless instructed otherwise. Avoid certain medications that could affect results.
How the Test Is Performed
You’ll use a special container to collect every drop of urine for the full 24 hours. The sample is then analyzed in a lab to measure sodium, potassium, and other urine components.
What the Results Mean
Results help identify if you’re losing too much or too little sodium/potassium, which can cause symptoms like muscle cramps, confusion, or irregular heartbeat. Abnormal levels may signal kidney issues or other health problems.
Reference range
NCBI: Uric Acid Male 3.5-7.2 mg/dL; Female 2.5-6.8 mg/dLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
24-Hour Urine Electrolytes (Na/K Diff)
Frequently asked questions
What might cause abnormal results?
How often should I get this test?
Can I drink alcohol before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy