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Serum Creatinine (Creatinine)

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

This test measures the level of creatinine, a waste product from muscle metabolism, in your blood to assess kidney function.

Quick summary

["Your kidneys filter waste from your blood; this test helps check how well they’re working."]

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

Key facts at a glance

LOINC
6570-6
Short code
VZV IgM Titr Ser IF
Synonyms
VZV IgM Titr Ser IF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
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 Is This Test Done?

Your doctor may order this test to evaluate kidney health, especially if you have symptoms like swelling, fatigue, or changes in urine output. It’s also used before certain procedures or surgeries to ensure your kidneys are functioning properly.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a broader panel. Drink plenty of water the day before to help dilute creatinine levels if needed.

What Happens During the Test?

A small blood sample is drawn from a vein, usually in your arm. The process is quick and typically painless. The lab will process the sample to measure creatinine concentration.

What Do the Results Mean?

Results are compared to a reference range, but exact values can vary by lab. High levels may indicate kidney problems, while low levels could suggest dehydration or muscle disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine

Frequently asked questions

Will I Need to Avoid Certain Foods or Drinks Before the Test?
Generally, no special diet is required, but avoid excessive protein intake 24 hours before testing, as it may slightly alter creatinine levels. Hydration is usually encouraged unless your doctor advises otherwise.
How Long Will I Wait for My Results?
Results are typically available within 1–3 business days, depending on your lab. Follow-up with your doctor if you have questions about your specific results.
Can Creatinine Levels Change Based on My Activity Level?
Yes, muscle mass and activity levels can influence creatinine levels. People with higher muscle mass or intense exercise may have slightly elevated levels, but this is usually normal unless accompanied by other symptoms.
  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