24-Hour Sodium Urine Collection (Total Sodium Content)
This test measures the total amount of sodium found in your urine over a 24-hour period. Sodium is an important electrolyte that helps balance fluids and maintain proper nerve and muscle function.
["Helps assess kidney function and sodium balance over a full day’s output."]
Key facts at a glance
- LOINC
- 43423-3
- Short code
- Na Urate 24h SatFr Ur
- Synonyms
- Na Urate 24h SatFr Ur
- Category
- electrolyte
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 20
- Ref high
- 400
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82670
- 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 Is This Test Done?
Your doctor may order this test to evaluate how well your kidneys are removing sodium from your body. It can help diagnose conditions like kidney disease, excessive sweating, or certain hormonal imbalances that affect sodium levels.
What to Expect Before the Test
You’ll need to collect all urine for 24 hours, starting after midnight on one day and ending just before midnight the next. Drink plenty of fluids but avoid foods high in sodium unless instructed otherwise. Your lab technician will provide detailed instructions to ensure accuracy.
How the Test Works
After your urine collection is complete, it’s sent to a lab where the total sodium content is measured. The result is compared to standard values to determine if your sodium excretion is within normal limits or if further evaluation is needed.
What the Results Mean
Results may indicate whether your kidneys are efficiently removing sodium, or if there’s an imbalance due to factors like dehydration, kidney issues, or certain medications. Your doctor will discuss these findings with you in the context of your overall health.
Reference range
Premenopausal: 20-400 pg/mL; Postmenopausal: <30 pg/mLN/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.
◆Associated findings1
Short name
24h Na Urine
Frequently asked questions
Why might my doctor ask me to collect urine for 24 hours?
What should I do if I forget to collect urine at the right time?
Can I eat or drink anything special 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 16, 2026. · Read our editorial policy