Lab test glossary · Inflammation
C-Reactive Protein: what it means
Also known as: CRP, hs-CRP
CRP is a marker of inflammation that rises with infection, injury, or chronic inflammatory conditions — nonspecific but sensitive.
What it measures
C-reactive protein is made by the liver and rises quickly when there's inflammation anywhere in the body. It doesn't say where or why — it's a sensitive but nonspecific signal. A high-sensitivity version (hs-CRP) is sometimes used to help gauge cardiovascular risk.
Typical range
A standard CRP under about 10 mg/L is common; for hs-CRP used in heart-risk assessment, under 1 mg/L is considered lower risk and above 3 mg/L higher risk.
Reference ranges differ between labs and are printed on your own report — always read your result against that range, not a general one.
What a high result can mean
- Infection or recent injury/surgery
- Chronic inflammatory or autoimmune conditions
- Obesity and, at low levels, cardiovascular risk
A high value is a starting point for a conversation, not a diagnosis — many causes are benign or temporary.
Why the trend matters
CRP spikes with any acute illness, so one high value often just means you were fighting something that day — the trend across well visits is more meaningful.
When to talk to your doctor
A persistently elevated CRP without an obvious infection is worth discussing with your doctor.
Frequently asked questions
What does a high CRP mean?
CRP rises with inflammation anywhere in the body — infection, injury, or a chronic inflammatory condition — but it doesn't say where or why, so it's a sensitive but nonspecific signal.
What is a normal CRP level?
A standard CRP under about 10 mg/L is common; the high-sensitivity version (hs-CRP) used for heart-risk assessment reads under 1 mg/L as lower risk and above 3 mg/L as higher.
Can CRP be high from a cold or infection?
Yes — any recent infection or illness can raise CRP, which is why one high value often just reflects that your body was fighting something.
This page is general education about a common lab test — it isn’t medical advice and can’t interpret your specific result. What a value means depends on your history, symptoms, and the rest of your labs, which is a conversation for you and your clinician.