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Serum or Plasma Creatinine 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 by tracking 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
36786-2
Short code
MRA UE vv-L
Synonyms
MRA UE vv-L
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
mr-angio
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

You can eat and drink normally before this test. If you’re on dialysis, follow your doctor’s instructions. Avoid taking certain medications (like NSAIDs) that may affect kidney function, but always check with your provider first.

During the Test

A small needle is inserted into your arm to draw blood. The process is quick and usually painless. You may feel a brief pinch, but most people tolerate it well.

After the Test

You can return to your normal activities immediately. Apply gentle pressure to the site to stop any bleeding. If you experience excessive bruising or pain, contact your doctor.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine Level

Frequently asked questions

Your creatinine levels help determine how well your kidneys are working. High levels may indicate kidney damage or disease, while low levels could suggest dehydration or muscle breakdown. Your doctor will compare your results with your baseline and other health factors to interpret them accurately.
This test is often used alongside other kidney function tests, such as blood urea nitrogen (BUN), to get a full picture of kidney health.
How often should I get this test if I have kidney-related conditions?
Your doctor will decide how often you need this test based on your specific condition, symptoms, and overall health. Regular monitoring helps track changes and adjust treatments if needed.
Can diet or exercise affect my creatinine levels?
Diet high in protein can temporarily raise creatinine levels, so your doctor may recommend monitoring or adjusting your diet. Exercise generally doesn’t affect creatinine levels, but staying hydrated is important for kidney function.
  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