Skip to content

Serum Creatinine (Mass Concentration)

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

This test measures the level 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 doctors evaluate kidney health and guide treatment plans."]

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

Key facts at a glance

LOINC
85373-9
Short code
Neut.fMLP DHR/Neut fMLP NFr Bld FC
Synonyms
Neut.fMLP DHR/Neut fMLP NFr Bld FC
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why It’s Done

Your doctor may order this test if you have symptoms like swelling, fatigue, or frequent urination, or if they suspect kidney problems. It’s also used to monitor kidney function in people with diabetes, high blood pressure, or other chronic conditions.

What to Expect

A small blood sample is taken from a vein in your arm. The process is quick and usually painless. No special preparation is needed unless your doctor instructs otherwise.

Normal vs. Abnormal Results

While reference ranges vary by lab, higher than expected levels may suggest kidney issues, while very low levels could indicate muscle disorders or dehydration. Your doctor will interpret results in the context of your overall health.

Common Causes of Changes

Kidney disease, dehydration, muscle breakdown, or certain medications can affect creatinine levels. High levels may also occur with heart or liver problems.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Creatinine is a key marker for kidney function. It reflects how well your kidneys remove waste from your blood. Elevated levels often signal impaired kidney function, prompting further evaluation for conditions like chronic kidney disease or acute kidney injury. Your doctor may use these results to adjust medications, monitor treatment progress, or plan interventions.

Short name

Creatinine

Frequently asked questions

How often should I get this test?
Your doctor will determine the frequency based on your health status. For example, people with kidney disease may need tests more often than others.
What does it mean if my creatinine level is high?
A high level may indicate poor kidney function or other health issues. Your doctor will discuss findings with you and may recommend lifestyle changes, further tests, or treatment adjustments.
Can diet affect creatinine levels?
Dietary protein intake can influence creatinine levels, but the impact is usually small. Your doctor may advise limiting high-protein foods if kidney function is compromised.
  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