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Serum Creatinine (Creatinine Level)

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

["Kidney function depends on this test to detect early kidney problems."]

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

Key facts at a glance

LOINC
18579-3
Short code
J Pnt ST Amp+80ms L-V6
Synonyms
J Pnt ST Amp+80ms 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 Is This Test Done?

Your doctor may order this test to check for kidney disease, monitor kidney function over time, or evaluate symptoms like swelling, fatigue, or changes in urine output. It’s also used before certain procedures or surgeries to assess kidney health.

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 ensure accurate results.

What Happens During the Test?

A healthcare provider will draw blood from a vein in your arm. The process is quick and usually causes only mild discomfort. The sample is sent to a lab for analysis.

What Are Possible Results?

Results are compared to a general reference range, but your actual range may vary based on age, sex, and overall health. High levels may signal kidney issues, while low levels could indicate muscle disorders or dehydration.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Creatinine

Frequently asked questions

How long does it take to get my results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Follow-up with your doctor if you have questions or concerns about your results.
What causes creatinine levels to be too high?
High creatinine levels may result from kidney disease, dehydration, severe muscle breakdown, or certain medications. Chronic kidney disease is the most common cause, but other factors like heart failure or high blood pressure can also play a role.
Can diet affect creatinine levels?
Dietary changes alone won’t alter creatinine levels, but eating a balanced diet rich in protein and staying hydrated can help support kidney function. Avoid excessive protein intake without medical guidance, as it may stress kidneys over time.
  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