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Serum Creatinine Concentration (Qualitative/Quantitative)

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

["Creatinine levels help determine how well your kidneys filter blood."]

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

Key facts at a glance

LOINC
19778-0
Short code
Indications description Endscpy
Synonyms
Indications description Endscpy
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
0.8
Ref high
1.2
Critical range
— – 5 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
endoscopy
CPT
85610
SNOMED
396252006
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 Is Done

Your healthcare provider may order this test to check for kidney problems, monitor kidney disease progression, or evaluate kidney function before certain procedures or surgeries. It can also help diagnose conditions like chronic kidney disease or acute kidney injury.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if your doctor specifies it, but this is not always required. Bring any medications you’re currently taking to your appointment.

What Happens During the Test

A healthcare professional will draw blood from a vein, typically in your arm. The process is quick and usually painless. You may feel a slight pinch, but it shouldn’t last long.

What the Results Mean

Results are compared to a general reference range, though exact values can vary by lab. High levels may indicate kidney issues, while very low levels could suggest muscle disorders or other health concerns. Your doctor will interpret results in the context of your overall health.

Reference range

INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A

Specimen: serum

Inform your healthcare provider if you are taking blood thinners. No special preparation required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Creatinine (Qual/Quant)

Frequently asked questions

Why might my creatinine levels be checked regularly?
Regular creatinine checks help track kidney function over time, especially if you have a history of kidney disease, diabetes, high blood pressure, or other conditions that can affect kidneys. It’s also used to adjust medications that kidneys clear from your body.
What does a high creatinine level usually mean?
A high creatinine level often signals impaired kidney function, meaning your kidneys aren’t filtering blood as well as they should. This can be due to kidney disease, dehydration, or other health issues. Your doctor will discuss further steps if needed.
Can diet affect creatinine levels?
Dietary changes, such as eating more protein, can temporarily raise creatinine levels. However, your doctor will consider your overall diet and health when interpreting results. Avoiding excessive protein intake before testing may help stabilize results.
  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