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Serum or plasma mass concentration of sodium

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

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.

Quick summary

["Sodium levels help diagnose and monitor 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
72385-8
Short code
EDDP Sal Cfm-mCnc
Synonyms
EDDP Sal Cfm-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
0
Ref high
4
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
confirm
CPT
84153
SNOMED
39392002
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 Sodium Levels Matter

Sodium is vital for maintaining proper fluid balance in your body, transmitting nerve signals, and helping muscles contract. Too much or too little can lead to serious health problems, such as swelling, muscle cramps, or even heart problems.

What Could Affect Your Results

Several factors can influence sodium levels, including diet (especially salt intake), dehydration or fluid overload, certain medications (like diuretics), kidney disease, and hormonal imbalances.

When You Might Need This Test

Your doctor may order this test if you have symptoms like excessive thirst, confusion, swelling, or if you’re being treated for conditions like high blood pressure, kidney disease, or heart problems.

Common Conditions Monitored

High sodium levels (hypernatremia) can occur in dehydration, kidney failure, or excessive salt intake, while low sodium levels (hyponatremia) may result from overuse of diuretics, vomiting, or certain medical conditions.

Reference range

Normal: <4.0 ng/mLN/A

Specimen: serum

No special preparation required. For PSA, avoid sexual activity for 24-48 hours before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Sodium level

Frequently asked questions

What does a normal sodium level mean for me?
A normal sodium level doesn’t mean your body is perfectly balanced—it just means your test result falls within the typical range for healthy adults. Your doctor will consider your overall health, symptoms, and other test results to determine if your sodium level is appropriate for you.
How can I prepare for this test?
Most sodium tests don’t require special preparation. However, if you’re taking diuretics or have kidney issues, your doctor may advise you to avoid certain foods or fluids before the test.
Will this test hurt?
No, this test involves a simple blood draw, which may cause a slight pinch or discomfort for a few seconds. Most people find it brief and manageable.
  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