24-Hour Urinary Potassium Excretion
This test measures how much potassium your body excretes in urine over a full day. Potassium is an important electrolyte that helps regulate heart rhythm, muscle function, and fluid balance.
["Understanding your daily potassium loss helps doctors assess kidney function and electrolyte balance."]
Key facts at a glance
- LOINC
- 59162-8
- Short code
- Potassium 24h Stl-sCnc
- Synonyms
- Potassium 24h Stl-sCnc
- 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, abnormal electrolyte levels, or conditions like hyperaldosteronism (excessive potassium loss) or hypokalemia (low potassium). It can also help monitor long-term kidney health or evaluate responses to certain medications.
How the Test Works
You’ll collect all urine for a full 24-hour period in a special container. The sample is then sent to a lab for analysis to determine the total potassium content excreted in your urine.
Sample Collection and Preparation
To ensure accurate results, collect all urine—including first-morning urine—over a 24-hour period. Store the sample in a cool place and return it to your lab or doctor promptly. Avoid using sanitizers or cleaning agents that might affect the test.
What to Expect Before the Test
No special preparation is needed, but drink plenty of water to help your kidneys produce urine throughout the day. Avoid excessive salt intake unless directed otherwise by your doctor.
Reference range
Adult: 3.5-5.0 mmol/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
High urinary potassium excretion may indicate kidney dysfunction, excessive sweating, or certain medications that increase potassium loss. Low excretion could suggest kidney retention of potassium, dehydration, or conditions like Addison’s disease. Regular monitoring helps manage long-term health risks and adjust treatments as needed.
Short name
Urine Potassium (24-hour)
Frequently asked questions
What does a high or low result mean?
Does diet affect this test?
How often should I get 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