Potassium concentration in urine
This test measures how much potassium your body excretes through urine, helping assess kidney function and electrolyte balance.
["Urine potassium helps check kidney health and fluid/electrolyte balance."]
Key facts at a glance
- LOINC
- 35677-4
- Short code
- Potassium ?Tm Ur-sCnc
- Synonyms
- Potassium ?Tm Ur-sCnc
- Category
- electrolyte
- 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
Why is this test done?
Your doctor may order urine potassium testing if you have symptoms like muscle weakness, irregular heartbeat, or signs of kidney problems. It can also help diagnose conditions like kidney disease, metabolic disorders, or excessive sweating that leads to low potassium levels.
What does the test involve?
A urine sample is collected, often over a 24-hour period (unless specified otherwise), to measure the amount of potassium naturally excreted in your urine. The sample is sent to a lab for analysis.
What might affect results?
Factors like diet (high potassium foods), certain medications, kidney function, and hydration levels can influence urine potassium levels. Avoiding certain foods or drinks before testing may help ensure accurate results.
How is the test prepared?
Follow your doctor’s instructions precisely. Typically, you’ll collect all urine for a full 24-hour period in a clean container, starting after waking up and ending just before waking up the next day. Drink enough fluids to produce urine throughout the day.
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.
Potassium in urine is critical for maintaining normal heart rhythm, muscle function, and nerve signaling. Abnormal levels can indicate kidney dysfunction, electrolyte imbalances, or other health issues requiring medical attention.
Short name
Urine Potassium
Frequently asked questions
What are common reasons for this test?
How long does it take to get results?
Can I eat or drink normally before 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