24-Hour Urinary Potassium Excretion
This test measures how much potassium your body excretes in urine over a 24-hour period. It helps assess kidney function and electrolyte balance.
["Understanding your potassium loss can help diagnose kidney issues or other health conditions."]
Key facts at a glance
- LOINC
- 9077-9
- Short code
- Potassium intake 10h
- Synonyms
- Potassium intake 10h
- Category
- electrolyte
- Sample
- serum
- Container
- Red-top tube (SST)
- 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 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 muscle weakness, cramps, or irregular heartbeat. It’s also used to check kidney function, especially if you’re taking medications that affect potassium levels or have conditions like kidney disease.
What to Expect Before the Test
You’ll need to collect all urine for 24 hours, typically starting after midnight the day before the test. Drink plenty of fluids but avoid potassium-rich foods (like bananas, spinach, or salt substitutes) unless your doctor advises otherwise.
How the Test Works
The collected urine is sent to a lab, where potassium levels are measured. The test helps determine how much potassium your kidneys are filtering out.
Possible Results and Interpretation
Low potassium excretion may indicate kidney problems or medications that reduce potassium loss. High excretion could suggest kidney disease or other metabolic issues. Your doctor will interpret results in relation to your overall health.
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.
Clinical Significance: How This Test Helps Healthcare Providers
Short name
24h Urinary Potassium
Frequently asked questions
How much potassium is in my urine over 24 hours?
Can I eat or drink anything special before this test?
What does a low or high potassium excretion mean?
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