C-Reactive Protein: What Is It, Normal Range & High Levels (2024)

C-reactive protein (CRP)is a protein produced by the liver. It is made in highamountswhen there is some type of inflammatory or infectious process occurring in the body, and is often one of thefirst signs of a blood testabnormality.

This protein is usually used to assess the possibility of a non-visibleinfection or inflammatory process, such as appendicitis, atherosclerosis, or viral andbacterial infections. However, C-reactive protein testingcan also assess the risk of a person developing cardiovascular diseases, as high levels are generally associated with a high risk for developing disease.

The CRP test does not identify where theinflammation or infection is occurring specifically, but an elevatedCRP levelshows that the body is fighting a foreign invader. This may also be noted in the white blood cell count.Since there may be different variables at play, CRP test results should always beevaluated by the doctor who ordered the test.

Normal CRPlevels

Normal CRP levels, for bothmen and women can varyup to 3.0 mg/L or 0.3 mg/dL. In relation to cardiovascular risk, the intervals that indicate the probability of developing a heart disease are:

• Highrisk: above3.0 mg/L;
• Mediumrisk: between1.0 and3.0 mg/L;
• Low risk: less than1.0 mg/L.

C-reactive proteinlevels shouldbe between1 and3 mg/L. Low levels of CRP can also be seen in some cases, such aspeople who have undergonegreatweight loss, people who do a lot of physical activity, people who consume a lot ofalcoholand those who use certain types of medication.It is therefore important for a doctor to identify the underlyingcause.

CRP test results should always be interpreted by a doctor, asit's important for theresults and initialassessment to be analyzedtogether to achievean accurate diagnosis.

What ishigh-sensitivityCRP (hs-CRP) test

The high-sensitivity CRP (hs-CRP) test is prescribed when the doctor wants to assess the person's risk of developingcardiovascular problems, such as heart attack or stroke. In this case, the test is requested when the person is healthy, and doesn't have any symptoms or apparentinfection. This exam is more specific,and it can detect very small amounts of CRPin the blood.

If someoneis apparently healthyand presents with high CRPlevels, this means that this personhas a higher risk of developing peripheral arterydisease, or having a heart attack or a stroke. In this cases,it's usuallyrecommendedto starta healthy diet and practiceregular physical activity, in order to improve cardiachealth.

What causes high CRPlevels

High levels ofC-reactiveprotein normally occur when there is some type ofinflammatory or infectious processoccurring in thebody.

In some cases, the CRPamounts can indicate the gravity of theinflammation or infection:

• Between3.0 to10.0 mg/L: generally indicatemildinflammation or infection like gingivitis, flu or cold;
• Between 10,0 to 40,0 mg/L:can be a sign of a moderate infection, such as chickenpoxor respiratoryinfection;
• More than40 mg/L:generallyindicate a more serious bacterial infection;
• More than 200 mg/L: mayindicate septicemia, a very serious situation that can be life threatening.

An increase in CRP levelscan also signalchronic disease and so the doctor may prescribe other examstoevaluate what could be causing the CRP levels toincrease.

What to do when the CRPis high

After confirminghigh levels of CRP, the doctor willevaluatethe results ofothertests andassessthe patient’s symptoms.From the moment the cause is identified, treatment can be started in a more focused and specific way.

When the patient shows signs ofmalaise without any other symptoms or specific risk factors, the doctor may request other exams, such as blood tumor marker tests or a CT scan, to check ifincreased levelsof CRPare related to cancer.

When C-reactive proteinlevels are above200 mg/L and an infection is confirmed, normally the person will be hospitalized to receive intravenous antibiotics. The CRP levels start to increase 6 hours after any infection starts and will usually start to lower afterantibiotics. If CRP levels have not decreased aftertwo days,it's important that the doctor establishanother treatment strategy.