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C-reactive protein (CRP) measured by nephelometry in serum/plasma

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

This test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation in your body.

Quick summary

["CRP helps identify and monitor inflammation, often used to check for infections, autoimmune conditions, or other health issues."]

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

Key facts at a glance

LOINC
104815-6
Short code
C trach DNA Spec Ql
Synonyms
C trach DNA Spec Ql
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
molgen
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 CRP Matters in Your Health

CRP is a marker that signals inflammation, which can occur due to infections, injuries, or certain diseases like arthritis or heart disease. High levels may indicate an active inflammatory process that your body is responding to.

What Triggers CRP Levels to Rise

Your CRP levels can increase due to infections (like a cold or flu), injuries, surgeries, or certain medical conditions such as autoimmune diseases. Stress, smoking, and some medications can also influence CRP levels.

When You Might Need This Test

Doctors may order CRP tests to diagnose or monitor conditions like infections, arthritis, heart disease, or to check for signs of inflammation before or after treatments.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it’s part of a broader panel, but this is not always required for CRP alone. Bring any medications you’re currently taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP’s Role in Health

Short name

CRP (Serum/Plasma)

Frequently asked questions

What does a high CRP level mean?
A high CRP level suggests inflammation is present in your body. While it doesn’t specify the cause, it can help guide treatment decisions, such as adjusting medications for autoimmune diseases or planning care for infections.
How often should I get this test?
The frequency depends on your medical condition and treatment plan. Your healthcare provider will determine how often you need CRP testing, such as monthly, quarterly, or annually, based on your needs.
Can lifestyle changes affect CRP levels?
Yes, lifestyle factors like diet, exercise, smoking, and stress can influence CRP levels. Reducing inflammation through healthy habits may lower CRP, but results vary by individual.
  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