Inflammation
CRP Test: What a High Result Actually Tells You
C-reactive protein (CRP) is made by the liver when there is inflammation anywhere in the body. It is one of the most requested tests and one of the most misread: CRP tells you that something is inflamed, never what or where.
Normal CRP range
What a high CRP means
A high CRP means an inflammatory process is active. A common infection can lift it sharply within a day or two and bring it down just as quickly once the illness passes; a persistent rise, with no obvious illness, is what tends to interest a doctor.
Common causes:
- Infection, including a passing viral one
- Injury or recent surgery
- Inflammatory joint or bowel conditions
- Ongoing inflammation from long-term conditions
What a low CRP means
A low CRP is the expected, reassuring result. It does not rule out every condition — some illnesses raise it very little.
Food & lifestyle that help
Favour
- Vegetables, fruit and whole grains
- Fish, dal and other lean protein
- Nuts and seeds
- Adequate sleep and regular activity alongside diet
Limit
- Fried and heavily processed food
- Sugary drinks and sweets
- Smoking, which keeps inflammation raised
When to see a doctor
See a doctor if CRP is high without an obvious explanation, stays high after an illness has settled, or comes with fever, weight loss, joint pain or night sweats. CRP is a prompt to look further, never a diagnosis on its own.
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Make my free plan →Frequently asked questions
What is a normal CRP level?
In most labs a standard CRP under about 6 mg/L is normal, though some report up to 10 mg/L. hs-CRP uses a much finer scale for cardiovascular risk. Always read the range printed beside your result.
Does a high CRP mean I have an infection?
Not necessarily. Infection is a common cause, but injury, surgery and inflammatory conditions raise it too. CRP shows that inflammation is present, not what caused it.
How quickly does CRP come down?
It responds fast. After a simple infection resolves, CRP typically falls back within days. A level that stays up is the more meaningful finding, and one to take to a doctor.