Sodium concentration in serum or plasma
This test measures the amount of sodium, a key mineral electrolyte, in your blood. Sodium helps balance fluids and maintain normal blood pressure and nerve/muscle function.
["Sodium levels help diagnose conditions like dehydration, kidney problems, or high blood pressure."]
Key facts at a glance
- LOINC
- 12908-0
- Short code
- Sodium Vitf-sCnc
- Synonyms
- Sodium Vitf-sCnc
- Category
- electrolyte
- Sample
- serum
- Container
- Red-top tube (SST)
- 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
- 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 Is This Test Done?
Your doctor may order this test to check for imbalances caused by conditions like kidney disease, heart problems, or excessive sweating. It’s also used to monitor treatments for conditions like hypertension or fluid retention.
What to Expect Before the Test
No special preparation is needed. You’ll have a small needle inserted into your arm or hand to draw blood. It usually takes a few minutes, and you may feel a brief pinch.
What the Results Mean
Results are compared to standard ranges, but exact values can vary by lab. Low sodium (hyponatremia) may cause headaches or confusion, while high sodium (hypernatremia) could lead to muscle spasms or irregular heartbeat.
Common Conditions Affecting Sodium Levels
Conditions like severe vomiting, diarrhea, or kidney issues can lower sodium. Overuse of salt, diabetes, or certain medications (like diuretics) may raise it. Chronic conditions like heart failure or liver disease can also influence levels.
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.
Sodium levels are critical for regulating fluid balance, nerve function, and blood pressure. Abnormalities can cause serious health risks, including seizures, coma, or heart problems. Regular monitoring helps manage conditions like hypertension or fluid imbalances.
Short name
Sodium Level
Frequently asked questions
What causes low sodium levels?
What causes high sodium levels?
How often should I get 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