Skip to content

Plasma Creatinine (Creatinine Level)

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

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

Quick summary

["Your kidney function is evaluated by checking how well your body removes creatinine from the blood."]

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

Key facts at a glance

LOINC
73105-9
Short code
Triamterene ind plt IgM SerPl Ql FC
Synonyms
Triamterene ind plt IgM SerPl Ql FC
Category
hematology
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
CPT
82784
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

Doctors order creatinine tests 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’re taking medications that may affect kidney function.

What to Expect Before the Test

No special preparation is needed, but avoid heavy exercise or eating a high-protein meal 24 hours before testing. Drink plenty of water the day of the test to help dilute creatinine levels.

How the Test Works

A blood sample is taken from a vein (usually in your arm). The lab analyzes the sample to measure creatinine concentration using a specialized chemical method.

What the Results Mean

Higher-than-normal levels may indicate kidney problems, while lower levels could suggest muscle breakdown or dehydration. Your doctor will compare results to your baseline and overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Creatinine levels are a key indicator of kidney function. Elevated levels often signal reduced kidney ability to filter blood, which can lead to long-term complications like fluid buildup, electrolyte imbalances, or even kidney failure if untreated. Regular monitoring helps manage conditions like diabetes or hypertension that may affect kidneys.

Short name

None

Frequently asked questions

How long does it take to get the results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your doctor will contact you once they’re ready for review.
What causes creatinine levels to be too high?
High creatinine levels can result from kidney disease, dehydration, severe muscle damage, or certain medications. Chronic conditions like diabetes or heart failure may also contribute.
Can diet affect creatinine levels?
Yes, high-protein foods or dehydration can temporarily raise creatinine levels. Avoiding excessive protein intake and staying hydrated may help stabilize 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