High CRP: what it means and what happens next
Medically Reviewed by Dr. Pedro Yelamo Vera, MD
Licensed Physician No. 484814280 · Official Medical College of Bizkaia (Spain)Last reviewed: 17 October 2026
High CRP in your blood test: infections, inflammation and other causes, why it rises and when it is worth reviewing with a doctor. Emergencies: 112.
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CRP (C-reactive protein) is the most commonly ordered inflammation marker in Spain, which is why it is the line most people find flagged on their report. It rises with almost any infection or inflammatory process, sometimes within hours, and falls once the cause resolves. The value says something active is going on, but never what it is on its own: it is read together with your symptoms.
What CRP measures and what the reference range looks like
CRP is a protein the liver produces in large amounts when there is inflammation in the body. A normal value is typically below about 10 mg/L in adults, and above that it is considered high. Peaks can reach several hundred mg/L in serious bacterial infections. Spanish reports abbreviate it as PCR or CRP, and many laboratories also measure a more sensitive variant (hs-CRP) for cardiovascular risk, which is interpreted with different thresholds.
Common causes of high CRP
- Infections: the most frequent cause. Bacterial infections tend to produce very high values; viral ones, more moderate rises.
- Chronic inflammatory conditions: rheumatoid arthritis, inflammatory bowel disease, lupus.
- Recent trauma or surgery: inflammation from tissue repair raises CRP for days.
- Obesity and smoking: they produce a mild chronic elevation that shows up often in routine checks.
- Late pregnancy: can raise CRP physiologically.
When waiting and repeating the test is usually enough
If you had the blood test while you had an infection — a cold, flu, gastroenteritis, tonsillitis — a high CRP is expected, and what is done is to repeat it 2–4 weeks after recovery. If it has fallen, there is nothing to investigate. A mildly high value without symptoms in someone with obesity or who smokes is also usually approached with general measures first, not with complex tests.
When it is worth reviewing sooner
- Very high values (for example, above 100 mg/L) without symptoms that clearly explain them.
- CRP that stays high on two or more checks, even moderately, with no known cause.
- Accompanied by persistent fever, weight loss or localised pain that is not improving.
- A notable change from your previous results without any change in your life.
Emergencies
High CRP is almost never an emergency on its own, but it is not a substitute for having an acute symptom assessed. If you have severe chest pain, severe breathing difficulty or confusion, do not wait for a video consultation: call 112 or go to your nearest emergency department.
High CRP on your report and nobody has explained it?
Dr. Pedro Yelamo Vera, a licensed GP in Spain, reviews your blood test by video consultation, in English or Spanish, and explains what is usually done next.
FAQ
What is a normal CRP value?
In adults, typically below about 10 mg/L; each laboratory prints its own reference range and hs-CRP uses different thresholds.
How long does CRP take to fall?
It can rise within hours and takes days to normalise once the cause resolves; that is why a repeat is scheduled weeks later, not the next day.
Does high CRP always mean infection?
No. Any inflammatory process, recent surgery or even smoking can raise it persistently and mildly.
Can an online doctor review my CRP?
Yes. The report is reviewed alongside your symptoms and history, and a decision is made on repeating it or ordering more tests, where clinically appropriate following a genuine evaluation.
Sources
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Medical Citations & Sources
This content is written and reviewed by a licensed physician with reference to the following official health authorities.
