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24-Hour Urine Sodium and Chloride Content (Quantitative)

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of sodium and chloride in your urine over a 24-hour period, helping assess kidney function and electrolyte balance.

Quick summary

["Helps diagnose kidney issues and electrolyte imbalances by tracking sodium and chloride excretion over a full day’s urine output."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
31109-2
Short code
OF .35% NaCl 24h Inc NFr RBC
Synonyms
OF .35% NaCl 24h Inc NFr RBC
Category
electrolyte
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
4.2
Ref high
5.9
Critical range
2 N/A – 7 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85041
SNOMED
900000000000003001
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if they suspect conditions like kidney disease, hypertension, or abnormal fluid balance. It helps evaluate how well your kidneys are handling sodium and chloride, which are essential for maintaining proper fluid and electrolyte levels in your body.

What to Expect Before the Test

You’ll need to collect all urine for a full 24-hour period, typically starting after midnight one day and ending the same time the next day. Drink regular fluids unless instructed otherwise, and avoid special diets that restrict sodium or chloride.

How the Test Works

After collecting your urine sample, it’s analyzed in a lab to determine the total sodium and chloride content. The results are compared to standard values to assess your kidney function and electrolyte balance.

Possible Results and Their Meaning

High sodium or chloride levels may indicate conditions like kidney problems, excessive sweating, or certain medications. Low levels could suggest kidney dysfunction, excessive urine loss, or other metabolic issues. Your doctor will discuss these findings with you.

Reference range

Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A

Specimen: serum

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

24h Urine Na+/Cl- Profile

Frequently asked questions

What causes abnormal sodium or chloride levels in urine?
Abnormal results may stem from kidney disorders (e.g., chronic kidney disease), hormonal imbalances, excessive sweating, or certain medications. Conditions like hypernatremia (high sodium) or hyponatremia (low sodium) can also affect urine sodium levels.
How often should I get this test?
Your doctor will determine the frequency based on your symptoms, medical history, and other tests. It’s often done periodically if you have kidney disease, hypertension, or other conditions affecting fluid and electrolyte balance.
Can diet affect this test results?
Yes, diets high in sodium or chloride can influence results. Follow your doctor’s instructions to avoid special diets unless specified otherwise, and drink normal fluids unless advised differently.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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