Electrolyte Panel (with 24-Hour Urine Collection for Sodium and Potassium)
This test measures key minerals in your blood and urine to check how well your body balances fluids and electrolytes, including sodium, potassium, and sometimes chloride.
["Helps assess kidney function, fluid balance, and electrolyte disorders."]
Key facts at a glance
- LOINC
- 45234-2
- Short code
- Date eligible & selected to start HIV Rx
- Synonyms
- Date eligible & selected to start HIV Rx
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- reported
- CPT
- 86701
- 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
What This Test Measures
Blood tests: Sodium (serum/plasma), Potassium (serum/plasma), Chloride (serum/plasma). Urine tests: Sodium (24-hour urine), Potassium (24-hour urine). Some labs may also include creatinine or blood urea nitrogen (BUN) as part of the panel.
Why It’s Done
Your doctor may order this test to diagnose or monitor conditions like kidney disease, heart problems, high blood pressure, or electrolyte imbalances. A 24-hour urine collection helps track how much sodium and potassium you excrete over time.
Sample Collection
Blood samples are drawn from a vein, usually in your arm. For the urine portion, you’ll collect all urine for a full 24-hour period in a special container. Follow your doctor’s instructions carefully to ensure accurate results.
Preparation
No special preparation is needed for blood tests, but for the urine collection, avoid certain foods (like salt) or medications that could affect results. Drink plenty of water unless advised otherwise.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal levels of electrolytes can cause symptoms like muscle weakness, confusion, irregular heartbeat, or swelling. High sodium or low potassium may indicate kidney issues, heart strain, or dehydration. Urine sodium/potassium helps identify how well your kidneys filter waste and balance fluids.
Frequently asked questions
How long does the urine collection take?
What if I miss a urine sample?
Some medications (like diuretics) can affect sodium/potassium levels. Ask your doctor or lab technician which medications to avoid or adjust during your collection period.
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