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24-Hour Urinary Potassium Excretion (Total)

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

This test measures how much potassium your body excretes in urine over a full day. It helps assess kidney function and electrolyte balance.

Quick summary

["Helps check if your kidneys are removing enough potassium from your body."]

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

Key facts at a glance

LOINC
27441-5
Short code
Potassium 24h Stl-sCnt
Synonyms
Potassium 24h Stl-sCnt
Category
electrolyte
Sample
stool
Container
Clean container
Units
N/A
Ref low
3.5
Ref high
5
Critical range
2.5 N/A – 6.5 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84132
SNOMED
110742001
Specimen volume
5 g
Stability
Refrigerated: 24h, Frozen: 7d
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if they suspect kidney problems, electrolyte imbalances, or conditions like hyperaldosteronism, which can affect how your body regulates potassium.

What to Expect Before the Test

You’ll need to collect all your urine for 24 hours, starting after you wake up and ending just before you wake up the next morning. Drink plenty of fluids but avoid potassium-rich foods (e.g., bananas, nuts, or salt substitutes) unless instructed otherwise.

What Happens During the Test

After collecting urine, it’s sent to a lab for analysis. No special preparation is needed beyond following the collection instructions.

What the Results Mean

Results help determine if your kidneys are removing potassium efficiently or if other health issues (like heart problems or certain medications) might be affecting your electrolyte levels.

Reference range

Adult: 3.5-5.0 mmol/LN/A

Specimen: stool

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24h Potassium Urine

Frequently asked questions

What causes abnormal potassium levels in urine?
Abnormal results may be due to kidney disease, certain medications (like diuretics), hormonal disorders (like hyperaldosteronism), or conditions affecting how your body absorbs or excretes potassium.
How is this test different from a regular potassium blood test?
This test measures total potassium lost in urine over 24 hours, giving a broader picture of your body’s potassium excretion. A blood potassium test checks current levels in your bloodstream, which can differ due to fluid balance or kidney function.
Can diet affect this test?
Yes, high-potassium foods (like bananas, spinach, or salt substitutes) can raise urine potassium levels. Your doctor will likely advise avoiding these unless they’re part of a specific diet plan.
  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