What is C-reactive protein (CRP)?
C-reactive protein (CRP) is a protein that the liver releases into the blood in greater amounts during inflammation. The CRP level is therefore a simple laboratory marker of inflammatory activity. It does not tell you where in the body inflammation is located.
CRP explained simply
During infections, injuries or other inflammatory processes, the immune system releases messengers such as interleukin-6. They prompt the liver to produce large amounts of CRP within hours. The blood level often rises sharply and falls again once the inflammation subsides. CRP is thus one of the classic inflammatory markers.
CRP is usually reported in milligrams per litre (mg/l) and always interpreted in context: the value is non-specific. It shows that something inflammatory is going on, but not what or where.
hs-CRP: the sensitive version
High-sensitivity CRP (hs-CRP) can measure very low levels accurately. Research uses it to capture mild, persistent inflammatory activity, for example in so-called silent inflammation. How to interpret a result in an individual case is for your doctor to decide.
What CRP is used for
Typical interpretation of the lab value (simplified, not a diagnosis)
| Situation | Typical CRP behaviour |
|---|---|
| Situation Acute infection or injury | Typical CRP behaviour Clear, rapid rise; falls after recovery |
| Situation Persistent low-grade inflammatory activity | Typical CRP behaviour Only slightly raised; captured with hs-CRP |
| Situation Studies on supplements | Typical CRP behaviour CRP serves as an outcome marker, not as proof of disease |
CRP in curcumin studies
Clinical studies often record CRP as a measure of inflammatory activity. For curcumin the results are not uniform: meta-analyses of randomised trials find on average a significant CRP reduction, individual studies show no change, and effects depend partly on duration and product. Dose, product, duration and study population differ widely, which makes comparison hard. A changed CRP value is also just a laboratory finding and not proof of a benefit in any disease.
Assessing the evidence as a whole therefore matters more than single numbers. This text is not medical advice.
How is CRP measured and which values are normal?
CRP is determined from a blood sample. As a rough guide, values below about 5 mg/l are considered unremarkable, though laboratories state their own reference ranges. In bacterial infections values of 50 mg/l and far more can be reached, whereas in viral infections they are often lower. For hs-CRP the range is much lower, in fractions of a milligram per litre.
These figures are guidance, not a diagnosis. How a value should be interpreted depends on symptoms, pre-existing conditions and other findings.
Frequently asked questions about CRP
How fast does CRP react? After inflammation begins, the level rises within about six to twelve hours and peaks after one to two days. It falls within a few days after the inflammation subsides.
Can a low CRP rule out inflammation? Not reliably. Some conditions cause only a slight CRP rise, so doctors always consider symptoms and other findings.
What else influences CRP? For example excess weight, smoking, lack of exercise or medication. A single value therefore says little; the trend matters.
