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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 and nerve function.

Quick summary

["Sodium levels help doctors check if you’re dehydrated, have kidney issues, or need electrolyte adjustments."]

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

Key facts at a glance

LOINC
88528-5
Short code
RSV RNA Corn/Cnjt Ql NAA+probe
Synonyms
RSV RNA Corn/Cnjt Ql NAA+probe
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
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 if you have symptoms like excessive thirst, confusion, muscle weakness, or irregular heartbeat. It’s also used to monitor conditions like heart failure, kidney disease, or high blood pressure.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm or vein to draw blood. If you’re on a sodium-restricted diet, let your doctor know before testing.

What the Results Mean

Low sodium (hyponatremia) can cause headaches, nausea, or seizures, while very high sodium (hypernatremia) may lead to dry mouth or muscle spasms. Your doctor will compare your results to your health history and other tests.

Common Causes and Conditions

Sodium levels can drop from vomiting, diarrhea, or excessive sweating, or rise from kidney problems, heart failure, or certain medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Sodium is critical for fluid balance, nerve signaling, and muscle function. Abnormal levels can indicate serious health issues like kidney failure, heart disease, or hormonal imbalances.

Short name

Sodium Level

Frequently asked questions

How often should I expect this test?
This test is often done once or twice a year if you have chronic conditions like kidney disease or heart failure. Your doctor will decide how often based on your needs.
What if my sodium level is out of range?
If your sodium level is too low, your doctor may recommend fluids, salt intake adjustments, or medications. If it’s too high, they might suggest reducing salt or fluids and monitoring closely.
Does diet affect sodium test results?
Yes, eating too much or too little salt can temporarily change your sodium level. Your doctor may ask you to avoid extreme salt intake before testing to get more accurate results.
  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