Understanding This Medical Test: What It Checks, Why Your Provider May Order It, How to Prepare, and What Your Results Can Mean
A test that measures the amount of chloride in urine collected over a 12-hour period to evaluate electrolyte balance and kidney function.
{"Measures chloride levels in urine collected over 12 hours","Helps diagnose electrolyte imbalances and kidney disorders","Collecting all urine during the 12-hour period is essential for accurate results","Results are affected by diet, medications, and certain medical conditions","Low or high chloride levels may indicate various health issues"}
Key facts at a glance
- LOINC
- 57340-2
- Short code
- CLU12
- Synonyms
- Chloride 12h Ur-sCnc
- Category
- electrolyte
- Sample
- urine
- Container
- Sterile plastic urine container, graduated collection container preferred
- Units
- not specified
- Ref low
- 55
- Ref high
- 125
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Ion-Selective Electrode (ISE) or Indirect Potentiometry
- CPT
- 82436
- SNOMED
- 271223006
- Specimen volume
- 10-100 mL from total 12-hour collection, aliquot for analysis
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C): 30 days. Preferred: refrigerate during collection.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 1–24 hours
- Order
- routine
What is this medical test, and what body function, condition, or substance is it being used to check for in your care?
The 12-hour urine chloride test measures the amount of chloride, an electrolyte, in your urine over a 12-hour collection period. Chloride is a mineral that helps maintain fluid balance, supports digestion by producing stomach acid, and works with other electrolytes like sodium and potassium to keep your body's chemistry balanced.
Why might your health care provider order this test, what signs or symptoms are being investigated, and how will it help guide decisions about your care?
This test is typically ordered to evaluate electrolyte balance, assess kidney function, or help diagnose conditions that affect chloride levels in the body. It may be used when a healthcare provider suspects electrolyte imbalances, kidney disease, certain metabolic disorders, or conditions affecting acid-base balance.
How should you prepare before this test, and how will your blood, urine, stool, tissue, or other sample be collected safely during the visit?
Your healthcare provider will provide specific instructions. Generally, you will be given a special container for urine collection. On the morning of the test, start by urinating and discarding that first sample. Then, collect all urine for the next 12 hours, including the first morning urine on the second day. Keep the container refrigerated or on ice during the collection period. Record the exact start and end times of collection.
What do your test results mean, how should they be interpreted with your history and other tests, and what questions should you ask your provider?
Normal urine chloride levels vary by laboratory, but typically range from 20-250 mmol per 12 hours. Low chloride levels may indicate certain kidney disorders, metabolic alkalosis, or conditions causing excessive chloride loss. High chloride levels may suggest high salt intake, certain medications, or conditions affecting electrolyte balance. Your healthcare provider will interpret your results based on your overall health and other test findings.
Reference range
Not established (diet/hydration dependent; typically 20-250 mmol/L)not specified
Complete 12-hour timed urine collection; refrigerate specimen during collection. No fasting or special diet required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
The 12-hour urine chloride test helps evaluate electrolyte balance and kidney function. Abnormal chloride levels can indicate kidney disease, metabolic disorders, dehydration, certain medications (like diuretics), or conditions affecting acid-base balance such as metabolic alkalosis or respiratory acidosis. This test is often used alongside other electrolyte tests (sodium, potassium) and kidney function tests to get a complete picture of your metabolic health.
Frequently asked questions
Does this test require fasting?
What happens if I miss collecting urine during the 12-hour period?
Can I take my regular medications before the test?
Is the test painful?
How long does it take to get results?
Sources
- 1
- 2Mayo Clinic - UrinalysisSource
- 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