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Serum or Plasma Creatinine Concentration (Mass Concentration)

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

["A creatinine test helps check kidney function and detect early kidney problems."]

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

Key facts at a glance

LOINC
14463-4
Short code
C trach Cvx Ql Cult
Synonyms
C trach Cvx Ql Cult
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
organism-specific-culture
CPT
86803
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 monitor kidney health, especially if you have symptoms like swelling, fatigue, or changes in urine output. It’s also used before surgeries, during pregnancy, or if you have conditions like diabetes or high blood pressure that can affect kidney function.

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 kidney function panel. Bring any medications you’re taking, as some (like certain pain relievers) can affect results.

What Happens During the Test?

A healthcare provider will draw blood from a vein in your arm. The sample is sent to a lab for analysis. The test typically takes a few minutes, and you can return to normal activities afterward.

What Do the Results Mean?

Higher than expected levels may indicate kidney problems, while lower levels could suggest dehydration or muscle breakdown. Your doctor will interpret results in relation to your overall health and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine Level

Frequently asked questions

What causes creatinine levels to be high?
High creatinine levels can result from kidney disease, dehydration, heart failure, severe muscle damage, or certain medications. If you notice symptoms like swelling, nausea, or frequent urination, discuss them with your doctor.
What if my creatinine level is low?
Low creatinine levels may suggest dehydration, low muscle mass, or liver disease. Your doctor might check other factors, such as urine output or hydration status, to understand the cause.
Do diet or exercise affect creatinine levels?
Dietary changes (like eating more protein) or intense exercise can temporarily raise creatinine levels. However, your doctor will consider your overall health and lifestyle when interpreting 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