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Serum or Plasma Sodium Concentration (Electrolyte Profile)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of sodium in your blood, which helps your body maintain proper fluid balance, nerve and muscle function, and blood pressure.

Quick summary

["Sodium levels help diagnose conditions like dehydration, kidney issues, or high blood pressure."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
34149-5
Short code
N-Ac-L-Asp Amn-sCnc
Synonyms
N-Ac-L-Asp Amn-sCnc
Category
chemistry
Sample
fluid
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your doctor may order this test if you have symptoms like excessive thirst, confusion, irregular heartbeat, or unexplained swelling. It’s also used to monitor conditions like heart failure, kidney disease, or electrolyte imbalances.

What to Expect Before the Test

No special preparation is needed. You may drink water beforehand, but avoid salty foods or diuretics (like caffeine) 24 hours before testing. Bring any medications you’re taking.

How the Test Is Performed

A healthcare provider will draw blood from a vein in your arm. You may feel a slight pinch, but it usually takes only a few minutes. The sample is sent to a lab for analysis.

What the Results Mean

Results are compared to a standard range for healthy adults. Very high or very low sodium levels can indicate serious health concerns that need medical attention.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Sodium Level

Frequently asked questions

What causes abnormal sodium levels?
Abnormal sodium levels can be caused by dehydration (too little water), kidney disease, heart failure, excessive sweating, vomiting, or certain medications (like diuretics). Lifestyle factors like high salt intake or excessive alcohol use may also play a role.
How long does it take to get results?
Test results are typically available within 1 to 2 business days, depending on your lab’s processing time. Your doctor will discuss the findings with you during your follow-up visit.
Can I eat or drink anything before this test?
Yes, you can drink water normally, but avoid salty foods, caffeine, or diuretics for 24 hours before testing. Follow your doctor’s specific instructions if you have any dietary restrictions.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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