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Serum or Plasma Sodium Slope (24-Hour Profile)

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

This test measures how sodium levels change over a 24-hour period in your blood or plasma. It helps assess kidney function and hydration status.

Quick summary

["Understanding how your sodium levels shift can help doctors track kidney health and fluid balance."]

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

Key facts at a glance

LOINC
10105-5
Short code
ST Slope L-V6
Synonyms
ST Slope L-V6
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 This Test Is Done

Your doctor may order this test if you have symptoms like confusion, swelling, or unexplained changes in blood pressure. It’s also used in patients with chronic kidney disease or those on medications that affect sodium levels.

What to Expect Before the Test

No special preparation is needed. You may have blood drawn from a vein in your arm, or a urine sample collected over 24 hours. If urine is involved, drink normal fluids and avoid diuretics unless instructed otherwise.

What the Test Results Mean

A consistent or increasing slope may indicate dehydration or kidney issues, while a decreasing slope could suggest overhydration or kidney dysfunction. Results are interpreted by your healthcare provider based on your overall health.

Common Conditions Monitored

This test helps monitor conditions like hyponatremia (low sodium), hypernatremia (high sodium), and kidney-related disorders. It’s also useful in patients on dialysis or those with heart or liver disease.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Sodium Slope Test

Frequently asked questions

How often will I need this test?
Your doctor will determine how often this test is needed based on your medical history, symptoms, and treatment plan. Some patients may need it monthly, while others may only require it occasionally.
What happens if my sodium levels are out of balance?
If your sodium levels are too high or too low, your doctor may adjust your medications, fluids, or treatment plan to restore balance. Severe imbalances can cause serious health risks, so prompt medical attention is important.
Can I eat or drink anything before the blood draw?
For blood tests, you can eat and drink normally. For urine collection, follow your doctor’s instructions regarding fluid intake and avoid certain medications or foods that could affect 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