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C-reactive protein, serum/plasma concentration (high-sensitivity)

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

This test measures the level of C-reactive protein (CRP) in your blood. CRP is a protein produced by your liver in response to inflammation, helping your body fight infections or injuries.

Quick summary

["hsCRP helps assess inflammation, a key marker for many health conditions."]

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

Key facts at a glance

LOINC
44994-2
Short code
C trach B IgM Ser Ql
Synonyms
C trach B IgM Ser Ql
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 Is This Test Done?

Your healthcare provider may order this test to monitor chronic conditions like heart disease, rheumatoid arthritis, or other inflammatory disorders. It can also help check for infections, evaluate response to treatment, or screen for early signs of inflammation-related issues.

What Does a High or Low Level Mean?

Elevated CRP levels often indicate inflammation, which can be linked to infections, autoimmune diseases, or other health problems. Very low levels may suggest no active inflammation, but they don’t rule out all causes. Your results will be interpreted by your provider in the context of your overall health.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The blood is sent to a lab where it’s analyzed to measure CRP levels using a sensitive immunoassay method.

What Can Affect Results?

Factors like recent illness, injury, stress, smoking, or certain medications (e.g., steroids) can temporarily raise CRP levels. Pregnancy, obesity, or certain chronic conditions may also influence results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP as an Inflammation Marker

Short name

hsCRP

Frequently asked questions

How often will I need this test?
Your provider will determine how often you need this test based on your medical history, symptoms, and treatment plan. Some people may need it monthly, quarterly, or less frequently depending on their condition.
What are the typical reference ranges?
Reference ranges vary by lab and may differ slightly between adults and children. A low CRP level (typically below 1 mg/L) often suggests minimal inflammation, while higher levels (above 3 mg/L) may indicate more significant inflammation. Your results are always interpreted with your overall health in mind.
Can I eat or drink before this test?
You may eat and drink normally before this test unless your provider gives specific instructions. Fasting is not required for CRP testing.
  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