Skip to content

C-reactive protein (CRP) 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 doctors assess inflammation, which can be linked to infections, injuries, or autoimmune conditions."]

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

Key facts at a glance

LOINC
106596-0
Short code
K oxytoca DNA Fld Ql NAA+n-prb
Synonyms
K oxytoca DNA Fld Ql NAA+n-prb
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
non-probe-amp-tar
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 Is This Test Done?

Your healthcare provider may order a CRP test to monitor inflammation, check for infections, evaluate autoimmune diseases, or assess risk for heart disease. It can also be used during recovery to see if inflammation is improving.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into a vein (usually in your arm) to draw blood. If you’re on blood thinners, let your provider know before the test.

What to Expect During the Test

The blood draw takes a few minutes. You might feel a brief pinch, but most people describe it as mild discomfort. You can resume normal activities afterward.

What the Results Mean

Results are typically reported in milligrams per liter (mg/L). Higher levels may indicate inflammation, while lower levels suggest minimal or no inflammation. Your provider will interpret results in the context of your health history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

CRP is a marker for inflammation, which is a natural response to injury, infection, or illness. Elevated CRP can signal conditions like infections (e.g., pneumonia), autoimmune diseases (e.g., rheumatoid arthritis), or chronic conditions (e.g., heart disease). It’s also used to monitor treatment effectiveness in some cases.

Short name

CRP Test

Frequently asked questions

How often should I get this test?
The frequency depends on your medical needs. Your provider may recommend it periodically if you have a chronic condition, recent surgery, or symptoms of inflammation. Follow their guidance—no routine screening is standard unless advised.
What does a high CRP level mean?
A high CRP level suggests inflammation is present. It doesn’t specify the cause, but it may prompt further testing (e.g., blood cultures, imaging) to identify infections, autoimmune activity, or other underlying issues. Your provider will discuss next steps with you.
Can diet or exercise affect CRP levels?
Yes! Lifestyle factors like diet (e.g., Mediterranean diet), exercise, and weight management can influence CRP levels. Reducing inflammation may lower CRP, so adopting healthy habits may help. Always consult your provider before making changes.
  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