Urine Potassium-to-Creatinine Ratio
Measures urinary potassium relative to urinary creatinine to help assess potassium balance and kidney handling of potassium.
["This urine test can help evaluate potassium excretion, especially when blood potassium results need further context."]
Key facts at a glance
- LOINC
- 111108-7
- Short code
- Potassium/Creat Msmt Ur
- Synonyms
- Potassium/Creat Msmt Ur
- Category
- kidney
- Sample
- urine
- Container
- Sterile urine 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
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
The urine potassium-to-creatinine ratio compares the amount of potassium in a urine sample with the amount of creatinine. Creatinine is used as a marker of how much urine was produced, helping the result estimate potassium excretion when using a spot urine collection.
Why might I need this test?
This test may be used to evaluate potassium balance and investigate abnormal blood potassium levels. It can also help assess how the kidneys handle potassium, including in evaluations for high blood pressure or possible excess aldosterone activity.
How is the test performed?
A urine sample is collected and analyzed in the laboratory. The laboratory measures potassium and creatinine and calculates the potassium-to-creatinine ratio. The result is interpreted with your other laboratory findings, medical history, and medications.
How do I prepare for the test?
Follow your clinician's urine-collection instructions, including whether a spot sample or timed collection is required. Tell the laboratory if you recently changed your potassium intake, used diuretics, had vomiting or diarrhea, or engaged in unusually strenuous exercise, because these can affect the result.
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.
A higher ratio may indicate increased potassium excretion, which can occur with high aldosterone activity, certain medications, low kidney potassium reabsorption, or recent potassium intake. A lower ratio may reflect low dietary potassium, gastrointestinal potassium loss, or reduced kidney function. The result must be interpreted with blood potassium levels and the clinical context.
Short name
Urine potassium/creatinine ratio
Frequently asked questions
Is this the same as a serum potassium test?
Why is creatinine included in the result?
What medications can affect 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