Sodium concentration rate over 1 hour (serum/plasma)
This test measures how much sodium your body loses or gains in one hour, often assessed in patients with conditions affecting fluid balance or kidney function.
["Understanding sodium changes helps doctors monitor fluid shifts and kidney function over time."]
Key facts at a glance
- LOINC
- 53122-8
- Short code
- Sodium 1h Ur-sRate
- Synonyms
- Sodium 1h Ur-sRate
- Category
- electrolyte
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 136
- Ref high
- 145
- Critical range
- 120 N/A – 160 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84295
- SNOMED
- 110741000
- 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 This Test Is Done
Doctors may order this test if you have symptoms like extreme thirst, swelling, confusion, or irregular heartbeat, which can indicate fluid or electrolyte imbalances. It’s also used in patients receiving IV fluids or those with kidney issues to track sodium levels over time.
What to Expect Before the Test
No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. If you’re receiving IV fluids, your sodium levels may be monitored closely during treatment.
What the Results Mean
Results show the rate of sodium concentration change per hour. A rapid increase or decrease may signal dehydration, overhydration, or kidney problems. Your doctor will interpret results in the context of your overall health and symptoms.
Common Conditions Monitored
This test is particularly useful for patients with chronic kidney disease, heart failure, or those on dialysis. It helps track how well your body is managing sodium levels during medical treatments.
Reference range
Adult: 136-145 mmol/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A sodium rate test helps identify rapid shifts in fluid balance that may not be obvious from a single blood test. For example, a sudden drop could indicate severe dehydration or kidney failure, while a rapid rise might suggest overhydration or improper fluid administration. Early detection allows for timely medical adjustments to prevent complications like seizures or heart strain.
Short name
Sodium rate (1-hour change)
Frequently asked questions
How long does it take to get results?
What does a ‘normal’ sodium rate mean?
Can I eat or drink 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