24-Hour Urinary Sodium Excretion Rate
This test measures how much sodium your body excretes in urine over a full day. It helps assess kidney function and how well your body regulates sodium balance.
["This test helps diagnose kidney issues or sodium imbalance over time."]
Key facts at a glance
- LOINC
- 21527-7
- Short code
- Sodium 24h Ur-mRate
- Synonyms
- Sodium 24h Ur-mRate
- Category
- electrolyte
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 136
- Ref high
- 145
- Critical range
- 120 N/A – 160 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84295
- SNOMED
- 110741000
- 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 if you have symptoms like high blood pressure, swelling, frequent urination, or signs of kidney problems. It can also help evaluate conditions like kidney disease, heart failure, or certain hormonal imbalances that affect sodium levels.
What Does the Test Involve?
You’ll collect all your urine for a full 24-hour period, typically starting after you urinate in the morning. The urine is then sent to the lab for analysis. The test measures the total sodium content in your urine over that time.
What Are Common Causes?
Conditions that may lead to this test include chronic kidney disease, heart failure, certain medications (like diuretics), or syndromes like Bartter syndrome or Gitelman syndrome, which affect sodium balance.
What If Results Are Abnormal?
High sodium excretion may suggest kidney issues, excessive sweating, or certain medications. Low sodium excretion could indicate kidney problems, dehydration, or conditions that restrict sodium loss (like certain hormonal disorders). Discuss any results with your doctor.
Reference range
Adult: 136-145 mmol/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: This test provides insight into how well your kidneys filter sodium and manage fluid balance. Abnormal results may indicate underlying conditions requiring medical attention, such as kidney dysfunction, electrolyte imbalances, or conditions affecting sodium retention or excretion.
Short name
24h Sodium Urine Rate
Frequently asked questions
How is the urine collection done?
What should I avoid before the test?
Can I take this test at home?
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