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Serum/Plasma Creatinine Concentration (Standard Method)

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

This test measures the amount of creatinine, a waste product from muscle metabolism, in your blood or plasma. It helps assess how well your kidneys are filtering blood.

Quick summary

["A creatinine test helps check kidney function by measuring 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
18047-1
Short code
LV EF US.2D.MOD-BP
Synonyms
LV EF US.2D.MOD-BP
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
us-d-mod-biplane
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 doctor may order this test if you have symptoms of kidney problems, such as swelling, fatigue, or changes in urine output. It’s also used to monitor kidney function in people with diabetes, high blood pressure, or other health conditions that can affect the kidneys.

What to Expect Before the Test

No special preparation is needed for this test. You may have a blood draw from a vein in your arm, or if it’s a urine sample, you’ll collect a small amount in a container. If you’re on a low-protein diet, discuss it with your doctor before the test.

What the Results Mean

Higher than expected creatinine levels may indicate poor kidney function, while lower levels could suggest overhydration or other conditions. Your doctor will interpret the results in relation to your overall health and medical history.

Common Causes of Abnormal Results

Creatinine levels can be affected by muscle mass, dehydration, or certain medications. Kidney disease, heart failure, or severe infections can also raise levels. If you have questions about your results, talk to your doctor.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine

Frequently asked questions

What symptoms might indicate I need this test?
Symptoms like swelling in your legs or ankles, frequent urination at night, fatigue, or unexplained weight gain could signal kidney issues. Your doctor may also recommend this test as part of a routine checkup or to monitor chronic conditions like diabetes or high blood pressure.
How often should I get this test if I have kidney-related conditions?
If you have kidney disease or are at risk, your doctor will determine how often you need this test based on your condition. Regular monitoring helps track changes and adjust treatments as needed.
Can diet or exercise affect my creatinine levels?
Yes, muscle mass and hydration levels can influence creatinine levels. Eating a balanced diet and staying well-hydrated can help maintain stable results, but your doctor should guide your specific lifestyle changes.
  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