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Serum or Plasma Creatinine Concentration (Quantitative)

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 kidney function by checking how well your kidneys filter blood.

Quick summary

["A creatinine test helps determine if your kidneys are working properly."]

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

Key facts at a glance

LOINC
23262-9
Short code
M cap caprip Ab Titr Ser
Synonyms
M cap caprip Ab Titr Ser
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 is a byproduct of muscle breakdown and is normally filtered out by your kidneys. If your kidneys aren’t working well, creatinine builds up in your blood. This test helps doctors monitor kidney health, especially in people with conditions like diabetes, high blood pressure, or those taking certain medications that can affect kidney function.

How the Test Works

A small blood sample is taken from your arm. The lab then measures the concentration of creatinine in your serum or plasma using a specialized test that detects its presence and quantity.

What to Expect Before the Test

You may be asked to fast for a few hours before the test, but this isn’t always required. Wear comfortable clothing and avoid heavy exercise on the day of the test. If you’re on dialysis, your doctor will guide you on when to schedule this test.

What to Expect During the Test

The test involves a simple blood draw from a vein in your arm. You may feel a slight pinch, but it usually takes only a few minutes. You can sit or lie down comfortably during the procedure.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine Level

Frequently asked questions

What does a high or low creatinine level mean?
High levels may indicate kidney problems, including reduced filtering ability, which could be due to conditions like chronic kidney disease, dehydration, or certain medications. Low levels might suggest overhydration, muscle loss, or liver disease, but they’re less common.
How often should I get this test?
Your doctor will determine how often you need this test based on your health history, symptoms, and overall condition. Regular monitoring is often recommended for people with kidney-related conditions or those at higher risk.
Can I eat or drink before this test?
Most of the time, you can eat and drink normally unless your doctor specifies otherwise. However, if fasting is required, follow your doctor’s instructions carefully to ensure accurate 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