Skip to content

Serum Creatinine (Creatinine)

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

This test measures the amount of creatinine, a waste product from muscle metabolism, in your blood serum. It helps assess kidney function.

Quick summary

["Your kidneys filter waste from blood; this test checks how well they’re doing."]

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

Key facts at a glance

LOINC
19162-7
Short code
VZV IgG Ser Ql
Synonyms
VZV IgG Ser Ql
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 Matters

Creatinine levels can indicate how efficiently your kidneys remove waste. High levels may signal kidney problems, while low levels could suggest dehydration or muscle breakdown. This test is often used alongside other kidney function tests to monitor overall kidney health.

What to Expect Before the Test

No special preparation is needed, but you may be asked to avoid certain medications or supplements that could affect results. Drink plenty of water the day before if you’re concerned about dehydration.

What the Results Mean

Results are typically compared to a reference range based on age, sex, and health status. Elevated levels may prompt further testing for kidney issues, while very low levels may need investigation for other causes.

Common Causes of Abnormal Results

High creatinine levels can result from kidney disease, dehydration, or conditions that reduce blood flow to the kidneys. Low levels may occur with severe muscle loss, liver disease, or overhydration.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine

Frequently asked questions

How often should I get this test?
Your doctor may recommend this test periodically if you have kidney-related conditions, high blood pressure, diabetes, or a family history of kidney disease. Follow-up testing frequency depends on your individual health needs and results.
Can diet or exercise affect creatinine levels?
Dietary protein intake can influence creatinine levels, but moderate changes are unlikely to cause significant fluctuations. Exercise may slightly alter levels due to muscle activity, but it’s not a major factor in routine testing.
What if my results are outside the normal range?
If your results are abnormal, your doctor will discuss next steps, which may include additional tests (like blood urea nitrogen or urine tests) or adjustments to your treatment plan. Always ask for clarification on what your results mean for you personally.
  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