Skip to content

C-reactive protein (CRP) serum concentration

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

This test measures the level of C-reactive protein in your blood, which is a marker of inflammation. It helps doctors assess whether inflammation is present in your body.

Quick summary

["CRP helps track inflammation, often used to monitor conditions like infections, autoimmune diseases, or after surgery."]

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

Key facts at a glance

LOINC
43844-0
Short code
C pneum IgM Ser Ql IF
Synonyms
C pneum IgM Ser Ql IF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
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 CRP Matters in Your Health

CRP is produced by your liver in response to inflammation. High levels can signal infections, injuries, or conditions like arthritis, heart disease, or certain cancers. It’s not specific to one disease but often used alongside other tests to guide treatment decisions.

When This Test Is Ordered

Your doctor may order CRP testing if you have symptoms like fever, joint pain, or signs of infection. It’s also used to check for inflammation before or after procedures, monitor chronic conditions, or evaluate responses to treatments.

What to Expect During the Test

A blood sample is taken from a vein, usually in your arm. You may feel a small pinch, but it’s quick and doesn’t require special preparation. Results are typically ready within a few days.

Common Conditions Monitored

CRP helps diagnose or track conditions like rheumatoid arthritis, heart disease, infections (e.g., pneumonia), or inflammatory bowel disease. It may also be used to assess risk after surgery or trauma.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP

Frequently asked questions

What Does a High CRP Level Mean?
A high CRP level suggests inflammation is present in your body. This could be due to infections, injuries, autoimmune diseases, or other conditions. Your doctor will consider your symptoms and other test results to determine the next steps.
What Does a Low CRP Level Mean?
A low CRP level usually means your body isn’t experiencing significant inflammation. However, it doesn’t rule out all causes of symptoms—other tests may be needed to investigate further.
Do I Need to Prepare for This Test?
No special preparation is needed. You can eat, drink, or take medications as usual. Avoiding strenuous activity for 24 hours before the test may help ensure accurate results, but this depends on your doctor’s instructions.
  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