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Serum or Plasma Sodium Concentration (Electrolyte Panel)

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

This test measures the amount of sodium, a key mineral, in your blood or plasma. Sodium helps regulate fluid balance and nerve/muscle function.

Quick summary

["Sodium levels help doctors check if you’re retaining or losing too much fluid or salt."]

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

Key facts at a glance

LOINC
63344-6
Short code
ENA SS-a 60kD Ab Titr Fld IA
Synonyms
ENA SS-a 60kD Ab Titr Fld IA
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
86430
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 diagnose or monitor conditions like dehydration, high blood pressure, kidney problems, or heart disease. It’s also used to check for electrolyte imbalances that could affect your daily activities or health.

What to Expect Before the Test

No special preparation is needed. You may drink water but avoid salty foods for a few hours before testing if instructed. Bring any medications you’re taking, as some can affect results.

What Happens During the Test?

A healthcare provider will draw blood from a vein in your arm. You may feel a small pinch, but it usually doesn’t cause discomfort. The blood is sent to a lab for analysis.

What the Results Mean

Results are compared to a standard range for healthy adults. Low sodium (hyponatremia) or high sodium (hypernatremia) can cause symptoms like confusion, muscle cramps, or irregular heartbeat. Your doctor will discuss results with you based on your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Abnormal sodium levels can indicate serious conditions, such as kidney disease, heart failure, or excessive sweating. Sodium imbalance may also signal underlying issues like diabetes or hormonal disorders. Regular monitoring is important for patients with chronic conditions like hypertension or kidney disease.

Short name

Sodium Level

Frequently asked questions

What causes sodium levels to be too high or too low?
High sodium levels may result from dehydration, excessive salt intake, or conditions like diabetes insipidus. Low sodium levels can occur from fluid overload, kidney problems, or certain medications.
How long does it take to get the results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your doctor will contact you once they’re ready.
Can I eat or drink anything before the test?
You can usually drink water but avoid salty foods for a few hours before testing unless your doctor advises otherwise.
  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