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C-reactive protein (CRP) by nephelometry

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

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

Quick summary

["CRP helps doctors track inflammation in your body."]

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

Key facts at a glance

LOINC
35976-0
Short code
CT LE-L
Synonyms
CT LE-L
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct
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 doctor may order a CRP test to check for signs of inflammation, monitor conditions like infections, autoimmune diseases, or heart disease, or evaluate how well a treatment is working. It can also help assess risk for certain health issues over time.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm or vein to draw blood. If you’re concerned about pain or discomfort, let your healthcare provider know.

What the Results Mean

Higher CRP levels often indicate inflammation, but the exact meaning depends on your overall health and symptoms. Your doctor will interpret the results in the context of your medical history and other tests.

Common Conditions Monitored

CRP is commonly used to monitor conditions like rheumatoid arthritis, lupus, heart attack risk, infections, or post-surgery recovery. It may also help guide treatment decisions for chronic illnesses.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP serves as a general marker of inflammation, reflecting the body’s immune response. Elevated levels can signal infections, autoimmune activity, or tissue damage, but it’s not specific to any single condition. Your doctor will use it alongside other factors to diagnose or manage your health.

Short name

CRP (Nephelometry)

Frequently asked questions

What does a high CRP level mean?
A high CRP level suggests inflammation is present, but it doesn’t point to a specific cause. It may indicate an infection, autoimmune disease, or other inflammatory conditions. Your doctor will discuss the results with you and may recommend further testing.
Can diet or exercise affect CRP levels?
Yes, lifestyle factors like diet, exercise, and smoking can influence CRP levels. Eating a heart-healthy diet, staying active, and avoiding smoking may help lower CRP and reduce inflammation over time.
Is CRP the same as a white blood cell count (WBC) test?
No, CRP measures a specific protein linked to inflammation, while a WBC test counts your immune cells. Both can be useful, but they serve different purposes in diagnosing conditions.
  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