Serum or Plasma Sodium Concentration (Electrolyte Profile)
This test measures the amount of sodium in your blood or plasma, an important electrolyte that helps balance fluids and support nerve and muscle function.
["Sodium levels help doctors check for dehydration, kidney issues, or other health concerns that may affect your body’s fluid balance."]
Key facts at a glance
- LOINC
- 10065-1
- Short code
- S' wave Amp L-V2
- Synonyms
- S' wave Amp L-V2
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ekg
- 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 It’s Done
Your doctor may order this test if you have symptoms like excessive thirst, confusion, swelling, or irregular heartbeat. It’s also part of routine checks for people with kidney problems, heart disease, or those taking certain medications that affect sodium levels.
What to Expect
A small blood sample is taken from your arm, usually at a lab or doctor’s office. The sample is sent to a lab where it’s analyzed to measure sodium concentration. Results are typically ready within a few hours to a couple of days, depending on the lab.
Normal vs. Abnormal Results
While reference ranges can vary slightly by lab, sodium levels are generally considered within a narrow range. Abnormally high or low levels may signal underlying health issues that need further investigation.
Common Causes of Abnormal Results
High sodium levels (hypernatremia) can occur due to dehydration, excessive salt intake, or certain medical conditions like diabetes insipidus. Low sodium levels (hyponatremia) may result from kidney problems, heart failure, vomiting, or excessive sweating.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Sodium Level
Frequently asked questions
How long does it take to get sodium test results?
Reference ranges for sodium levels can differ slightly between labs, but they generally fall between 135 and 145 milliequivalents per liter (mEq/L). These ranges can be influenced by factors like age, health conditions, and lab-specific methods.
Yes, sodium levels can fluctuate rapidly depending on factors like fluid intake, sweating, illness, or certain medications. If you experience symptoms like confusion, seizures, or extreme thirst, seek medical attention promptly.
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