Skip to content

24-Hour Urinary Sodium and Potassium Ratio (Qualitative)

Published: August 9, 2026Updated: August 16, 2026

This test measures the ratio of sodium and potassium in your urine over 24 hours to help assess how well your kidneys are balancing these minerals.

Quick summary

["Helps evaluate kidney function and electrolyte balance over a full day."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
71745-4
Short code
DAYCLOSED
Synonyms
—
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 you have symptoms like high blood pressure, swelling, frequent urination, or signs of kidney problems. It can also help diagnose conditions like kidney disease, adrenal disorders, or certain metabolic imbalances.

What to Expect Before the Test

You’ll need to collect all urine for 24 hours, starting and ending with a sample at the same time each day. Drink plenty of water but avoid foods high in sodium or potassium unless instructed otherwise.

How the Test Works

The collected urine is analyzed to determine the ratio of sodium and potassium. This ratio helps doctors assess how well your kidneys are filtering and balancing these minerals in your body.

What the Results Mean

An abnormal ratio may indicate problems with kidney function, hormonal imbalances, or other health conditions. Your doctor will interpret the results in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: This test is critical for diagnosing and monitoring conditions like primary hyperaldosteronism (high aldosterone), kidney disease, or conditions affecting sodium/potassium balance. It helps guide treatment decisions for conditions like hypertension or edema.

Short name

24h Urine Na/K Ratio (Qualitative)

Frequently asked questions

What does a ‘qualitative’ result mean?
A qualitative result provides a yes/no or category-based answer rather than a precise measurement. This test is designed to assess the ratio trend rather than exact values, so your doctor will use the qualitative result alongside clinical findings.
How is urine collected for this test?
You’ll need to collect every drop of urine for 24 hours, including the first morning urine. Store the samples in a refrigerator and bring the entire collection to your lab on the following day.
Can I take medications before this test?
Ask your doctor before taking any medications, especially those affecting sodium or potassium levels, as they may interfere with the test results.
  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 16, 2026. · Read our editorial policy