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C-reactive protein (CRP) measured by immunoassay (high-sensitivity) in serum/plasma

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

This test measures a protein in your blood that rises when your body is fighting inflammation, often used to check for subtle signs of inflammation or infection.

Quick summary

["Helps monitor low-level inflammation that may not show up in other tests."]

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

Key facts at a glance

LOINC
87949-4
Short code
C trach DNA Tiss Ql NAA+probe
Synonyms
C trach DNA Tiss Ql NAA+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-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 this test to assess general inflammation, evaluate risk for heart disease, or monitor conditions like arthritis, heart disease, or infections where inflammation plays a role. It’s sometimes used in routine check-ups for people at higher risk of cardiovascular issues.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a fasting panel. Bring any medications you’re currently taking to your appointment.

What the Test Results Mean

Results are not always straightforward—higher levels may indicate inflammation, infection, or other health concerns, while lower levels suggest minimal inflammation. Your provider will interpret results in the context of your overall health and symptoms.

Common Conditions Monitored

This test is often used to track conditions like rheumatoid arthritis, cardiovascular disease, or to screen for early signs of inflammation that could affect organs or joints.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

hs-CRP (high-sensitivity C-reactive protein)

Frequently asked questions

What does a high CRP level mean?
A high CRP level suggests your body is actively responding to inflammation, which could be due to infection, injury, autoimmune disease, or other health issues. Your provider will discuss this with you and may recommend additional tests.
Can I eat or drink before this test?
For most hs-CRP tests, you can eat and drink normally unless your provider specifies fasting. If fasting is required, follow their instructions carefully to ensure accurate results.
How long will it take to get my results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your provider will contact you once they’re ready to discuss them.
  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