24-Hour Urine Potassium (Total)
This test measures the total amount of potassium, a mineral important for heart function and nerve signaling, that you excrete in your urine over 24 hours.
["Helps assess kidney function and electrolyte balance over a full day’s urine output."]
Key facts at a glance
- LOINC
- 2830-8
- Short code
- Potassium Cl 24h Ur+SerPl-vRate
- Synonyms
- Potassium Cl 24h Ur+SerPl-vRate
- 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 Matters
Potassium is vital for maintaining normal heart rhythms, muscle function, and nerve communication. Your kidneys normally regulate potassium levels by filtering it into urine. A 24-hour urine test provides a complete picture of how much potassium your body is losing over time, which can help detect imbalances caused by conditions like kidney disease, certain medications, or excessive sweating.
When You Might Need It
Your doctor may order this test if you have symptoms like muscle weakness, irregular heartbeat, or signs of low potassium (hypokalemia), or if they suspect conditions like kidney problems, excessive vomiting/diarrhea, or certain medications (like diuretics) affecting potassium levels.
What to Expect Before the Test
You’ll need to collect all urine for 24 hours, starting right after you wake up. Empty your bladder at the start and end of the period, then store all urine in a special container. Avoid foods high in potassium (e.g., bananas, spinach) unless instructed otherwise.
What Happens During the Test
No special lab visit is needed—your urine sample is sent to a lab for analysis. The test measures total potassium content in your urine, not just the amount in your blood.
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.
Low 24-hour urine potassium levels may indicate kidney dysfunction, excessive vomiting/diarrhea, or medications that increase potassium loss. High levels could suggest kidney disease, certain cancers, or conditions that reduce urine output. This test helps diagnose and monitor electrolyte imbalances that affect heart and muscle health.
Short name
Urine Potassium (24-hour)
Frequently asked questions
How long does it take to get results?
What causes abnormal potassium levels in urine?
Can diet 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