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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

["A creatinine test helps doctors check how well your kidneys are filtering waste from your blood."]

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

Key facts at a glance

LOINC
88527-7
Short code
RSV Corn/Cnjt Ql Cult
Synonyms
RSV Corn/Cnjt Ql Cult
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
organism-specific-culture
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 can indicate how efficiently your kidneys are working. High levels may suggest kidney damage or disease, while low levels could be due to muscle mass changes or other conditions. This test is often used alongside other kidney function tests to diagnose and monitor kidney problems.

What to Expect Before the Test

You may be asked to fast for a few hours before the test, but this is not always required. Bring any medications you’re currently taking, as some may affect results. Avoid strenuous exercise or heavy meals 24 hours before the test to ensure accurate results.

How the Test Is Performed

A healthcare provider will draw blood from a vein in your arm using a small needle. You may feel a brief pinch, but the procedure is quick and usually painless. The blood sample is then sent to a lab for analysis.

Possible Results and Interpretation

Results are typically reported in milligrams per deciliter (mg/dL). While exact reference ranges can vary by lab, higher than expected levels may signal kidney issues, while lower levels might need further investigation to rule out other causes.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated creatinine levels are a key indicator of impaired kidney function. Chronic kidney disease (CKD) often presents with gradually rising creatinine levels, so regular monitoring is important for early detection. Additionally, creatinine can be influenced by factors like dehydration, muscle mass, or certain medications, so results should always be interpreted in the context of your overall health and medical history.

Short name

Creatinine

Frequently asked questions

What causes creatinine levels to be high?
High creatinine levels can result from kidney disease, dehydration, severe muscle damage, or conditions that affect blood flow to the kidneys. If you’ve recently had surgery, been ill, or taken certain medications, these could also temporarily raise your levels. Always discuss any symptoms or recent changes with your doctor.
How often should I get this test?
The frequency depends on your health. If you have kidney disease, your doctor may recommend regular testing every few months or annually. If you’re healthy, a baseline test may be done once, but follow-up depends on your risk factors (e.g., age, family history, or conditions like diabetes or hypertension).
Can diet or exercise affect creatinine levels?
Yes. High-protein diets or intense exercise can temporarily increase creatinine levels. Avoiding excessive protein intake for a day or two before testing may help stabilize results. Hydration is also key—drinking enough water can help maintain normal levels.
  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