Skip to content

Serum or Plasma Creatinine Concentration (Mass Concentration)

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

This test measures the amount of creatinine, a waste product from muscle metabolism, in your blood. It helps assess how well your kidneys are filtering blood.

Quick summary

["A creatinine test helps check kidney function and detect early kidney problems."]

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

Key facts at a glance

LOINC
110084-1
Short code
YFV IgM Msmt Ser
Synonyms
YFV IgM Msmt Ser
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 Matters

Your kidneys normally filter waste products, including creatinine, from your blood. If your kidneys aren’t working well, creatinine levels in your blood can rise. This test is often used to monitor kidney health, especially in people with risk factors like diabetes, high blood pressure, or a family history of kidney disease.

What to Expect Before the Test

No special preparation is needed for this test. You may have a blood sample drawn from a vein in your arm. If you’re on a low-protein diet or have recently exercised, your doctor may advise timing your test around these factors, but this is rare for creatinine.

Common Causes of Abnormal Results

High creatinine levels may indicate reduced kidney function, dehydration, or conditions like heart failure or muscle disorders. Low levels might suggest overhydration or certain liver diseases, though this is less common.

What the Results Mean

Results are typically compared to a reference range provided by your healthcare provider. While ranges can vary by lab, they help determine if your kidneys are working as expected. Your doctor will interpret results in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine

Frequently asked questions

Could my diet affect this test?
Yes, eating a high-protein diet or consuming large amounts of meat or supplements (like creatine) can temporarily raise creatinine levels. Your doctor may ask you to avoid these for a few days before testing if needed.
What if my creatinine level is high?
A high creatinine level often signals kidney strain, but it doesn’t always mean kidney disease. Your doctor may recommend follow-up tests or lifestyle changes to support kidney health, such as managing blood pressure or hydration.
Why do some labs use plasma instead of serum?
Plasma and serum are similar but differ slightly in composition. Plasma contains clotting factors, while serum does not. For creatinine, the difference is minimal, but labs may use plasma if the test is run immediately after drawing blood to avoid clotting.
  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