Skip to content

Serum Creatinine (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 serum. It helps assess kidney function.

Quick summary

["Kidney health check with a simple blood test."]

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

Key facts at a glance

LOINC
5622-6
Short code
Cr SerPl-mCnc
Synonyms
Cr SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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

Creatinine levels help doctors evaluate how well your kidneys are filtering waste from your blood. High levels may indicate kidney problems, while low levels could suggest dehydration or muscle breakdown.

What to Expect Before the Test

No special preparation is needed. You may eat and drink normally. If you’re on a low-protein diet or have certain medications, let your provider know beforehand.

Common Causes of Abnormal Results

Elevated creatinine may signal kidney disease, dehydration, or muscle disorders. Low levels might suggest overhydration or conditions affecting muscle metabolism.

How Results Are Interpreted

Results are compared to a reference range specific to your age, sex, and overall health. Your doctor will discuss what your numbers mean in your context.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Kidney Function Monitoring

Short name

Creatinine (Serum)

Frequently asked questions

What does a high creatinine level mean?
High creatinine levels often point to reduced kidney function, though other factors like muscle mass or dehydration can also influence results. Your doctor may recommend follow-up tests or adjustments to medications if needed.
Can diet affect creatinine levels?
Dietary protein intake can influence creatinine levels, but the test itself doesn’t measure protein directly. High-protein diets may temporarily raise levels, while dehydration can also spike them.
How often should creatinine be checked?
Frequency depends on your health status. People with kidney disease or risk factors may need regular monitoring, while others may only need it if symptoms arise or during routine check-ups.
  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