Skip to content

Serum Creatinine (Creatinine)

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 check: creatinine levels help determine how well your kidneys remove waste from your blood."]

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

Key facts at a glance

LOINC
101741-7
Short code
NSC #/area Smn HPF
Synonyms
NSC #/area Smn HPF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
microscopy-light-hpf
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 problems, while low levels could indicate dehydration or muscle breakdown. This test is often used alongside other measures like blood urea nitrogen (BUN) to evaluate kidney health.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to avoid certain medications or supplements that could affect results. Drinking plenty of water the day before can help ensure accurate results.

How the Test Works

A small blood sample is drawn from a vein, typically in your arm. The sample is sent to a lab where it is analyzed to measure creatinine levels using a specialized test method.

Common Causes of Abnormal Results

Elevated creatinine levels may be due to kidney disease, dehydration, or conditions that cause muscle breakdown. Low levels might indicate dehydration, overhydration, or certain muscle disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine

Frequently asked questions

What does my creatinine level mean?
Your creatinine level helps doctors monitor kidney function. If your levels are consistently high, it may signal kidney problems that need further evaluation, such as additional tests or treatments. Always discuss your results with your healthcare provider.
Can diet affect my creatinine test results?
Dietary changes, such as eating a lot of protein, can temporarily affect creatinine levels. However, your doctor will consider other factors, like kidney function and overall health, when interpreting your results. Avoid extreme dietary changes before testing if instructed.
How often should I get this test?
Your doctor will determine how often you need this test based on your health condition, medical history, and other factors. Regular monitoring may be recommended if you have kidney-related issues or risk factors like diabetes or high blood pressure.
  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