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C-reactive protein (CRP) concentration in 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 assess risk for conditions like heart disease or infection."]

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

Key facts at a glance

LOINC
45080-9
Short code
C trach rRNA Vag Ql Probe
Synonyms
C trach rRNA Vag Ql Probe
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe
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 this test to check for signs of inflammation, monitor chronic conditions (such as arthritis or heart disease), or evaluate symptoms like fever, pain, or swelling that could indicate infection or other health issues.

What to Expect Before the Test

No special preparation is needed. You may have blood drawn from a vein in your arm, similar to other blood tests. If you’re on blood thinners, let your provider know before the test.

What the Results Mean

Higher CRP levels often signal inflammation, which can be caused by infections, autoimmune diseases, or other health problems. Your provider will interpret results in the context of your overall health and symptoms.

Common Conditions Monitored

This test is commonly used to monitor conditions like rheumatoid arthritis, heart disease, or infections such as pneumonia or sepsis. It can also help track response to treatments.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP Plasma

Frequently asked questions

What Does a High CRP Level Indicate?
A high CRP level may suggest an active inflammatory process, such as an infection, autoimmune disease, or other conditions causing tissue damage. However, it can also be elevated due to stress, certain medications, or other factors.
What Does a Low CRP Level Indicate?
A low CRP level generally means there is less inflammation in your body, but it doesn’t rule out all causes of inflammation. Your provider will consider other factors, like symptoms and medical history.
How Often Should I Get This Test?
The frequency depends on your health condition and treatment plan. Your provider will determine how often to check CRP levels based on your individual needs, such as monitoring chronic diseases or responding to treatments.
  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