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C-reactive protein (CRP) by high-performance liquid chromatography (HPLC) or nephelometry

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

This test measures a protein your body produces in response to inflammation, helping detect or monitor conditions like infections, injuries, or autoimmune diseases.

Quick summary

["High CRP levels may signal inflammation that needs further evaluation by your healthcare provider."]

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

Key facts at a glance

LOINC
35901-8
Short code
CT Guided LN Bx
Synonyms
CT Guided LN Bx
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 this test to check for signs of inflammation, assess risk for heart disease, or monitor conditions like rheumatoid arthritis, lupus, or infections. High sensitivity CRP is often used when standard CRP levels are borderline or when early detection is important.

What Does a High or Low Level Mean?

Elevated levels often appear during infections, injuries, or inflammatory diseases. Very low levels may suggest no active inflammation, but this isn’t always the case—results should always be interpreted by your healthcare provider.

How Is the Test Performed?

A small blood sample is taken from your arm. The sample is sent to a lab where it’s analyzed using either HPLC or nephelometry to measure CRP levels accurately.

What Are Common Causes of Abnormal Results?

Increased CRP levels can be caused by infections (like pneumonia or urinary tract infections), autoimmune diseases (like lupus or rheumatoid arthritis), heart disease, or recent surgery. Low levels might indicate no active inflammation, but other factors could also play a role.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (High Sensitivity)

Frequently asked questions

What does a high CRP level mean for my health?
A high CRP level suggests inflammation is present, which could be due to infection, an injury, or an underlying condition like autoimmune disease. Your doctor will discuss next steps, such as further testing or treatment, based on your symptoms and overall health.
How often should I get this test?
Your doctor will determine how often you need this test based on your medical history, symptoms, and treatment plan. Regular monitoring may be recommended if you have conditions like heart disease or autoimmune disorders.
Can lifestyle changes affect CRP levels?
Yes, lifestyle factors like diet, exercise, and smoking can influence inflammation levels. Reducing stress, eating a balanced diet, and avoiding smoking may help lower CRP levels over time, but results can vary by individual.
  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