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Health Check

CRP – Inflammation marker

CRP shows whether there is ongoing inflammation or infection in the body. It is used in health checks to interpret other tests correctly and to catch inflammation that does not produce clear symptoms.

What is CRP?

CRP (C-reactive protein) is formed in the liver in response to inflammation. The level rises within a day of infection and falls rapidly as the inflammation heals.

Why is CRP measured in a health check?

Several other markers, such as ferritin and iron, are affected by inflammation. CRP is therefore needed to interpret them. Slightly elevated CRP over time can also be linked to cardiovascular risk.

High and low values

High value: Significantly elevated CRP indicates a bacterial infection or other pronounced inflammation. Slightly elevated values are seen in viral infection, overweight, smoking, and chronic inflammatory diseases.

Low value: Low values are normal and indicate no ongoing inflammation.

Reference ranges differ between laboratories, sexes and ages and are stated in your result. The information here does not replace medical assessment.

How CRP is measured in a health check

CRP is a protein produced by the liver during inflammation and rises quickly — often within six to twelve hours of something starting. The test is taken in a standard blood draw and requires no fasting. In a health check, CRP acts as a filter: it shows whether other results should be interpreted in light of ongoing inflammation.

If you've had a cold, tonsillitis, a dental infection or an injury in the past few weeks, CRP can be elevated without this meaning anything further. The same applies after surgery or very intense exercise. If you want a representative value, it's wise to wait about two weeks after recovering from an infection.

Why CRP affects the interpretation of other markers

Several common health-check markers change during inflammation, which can lead to misinterpretation if CRP isn't measured at the same time.

  • Ferritin rises with inflammation and can mask a genuine iron deficiency
  • Serum iron falls temporarily during infection
  • Albumin falls with prolonged inflammation
  • Blood lipids can be temporarily lower than normal
  • Leukocytes often rise in parallel with bacterial infection

Standard CRP and high-sensitivity CRP

Standard CRP is used to detect ongoing infection and inflammation. High-sensitivity CRP (hs-CRP) measures much lower levels and is instead used to describe the degree of low-grade inflammation, which research has linked to cardiovascular risk. The two tests answer different questions, and it's worth knowing which one is included in the health check you order.

A slightly elevated hs-CRP in someone who is overweight, has high blood glucose or a sedentary lifestyle is usually interpreted as part of an overall risk picture, not as a finding in itself. Lifestyle changes such as weight loss, quitting smoking and regular exercise often lower the value over time.

When a high CRP should be investigated

A markedly elevated CRP suggests an ongoing, often bacterial infection and should be assessed by a doctor, especially with fever or a general feeling of illness. Moderately elevated values that don't fall on repeat testing after a few weeks should also be investigated, since chronic inflammation can be linked to rheumatic disease, inflammatory bowel disease or other conditions requiring targeted investigation.

A normal CRP in a health check is also useful information: it suggests that other results aren't affected by ongoing inflammation, and that, for example, a low ferritin genuinely reflects empty iron stores.

Frequently asked questions about CRP

What does high CRP mean?

High CRP means the body has an ongoing inflammation or infection. How high the value is says something about how pronounced it is, but not where in the body it is located.

Should you wait for a health check if you have a cold?

Yes, it is usually wise. An ongoing infection raises CRP and can also affect ferritin and blood status, making the answers harder to interpret.

Can exercise raise CRP?

Yes, a hard session or a race can cause a temporary rise for a day or two. Rest before the test if the aim is to measure your baseline level.

What does a slightly elevated CRP without symptoms mean?

It could be remnants of an infection, a dental infection, excess weight or low-grade inflammation. Repeat the test after a few weeks before drawing conclusions.

Do CRP and hs-CRP differ?

Yes. Standard CRP detects infection and clear inflammation, while high-sensitivity CRP measures low levels and is used for risk assessment.

Why is CRP included in a health check with a blood test?

CRP shows whether you had ongoing inflammation when the sample was taken. This is needed to interpret markers such as ferritin and iron correctly, since they're affected by inflammation.

Health checks that include CRP

CRP is included in 10 of Labkollen's health checks. Analysis name in the result: CRP.

  • Man +

    49 markers

    Labkollens mest omfattande kontroll för män – inklusive testosteron, PSA och hjärt-kärlmarkörer.

    2 195 krMed prenumeration (årlig hälsokontroll): 1 756 kr

    See the test

  • Kvinna +

    44 markers

    Labkollens mest omfattande kontroll för kvinnor – inklusive järnstatus, sköldkörtel och hormoner.

    2 195 krMed prenumeration (årlig hälsokontroll): 1 756 kr

    See the test

  • Standard

    37 markers

    Bred hälsokontroll över blodsocker, blodfetter, blodvärde, lever, njurar, sköldkörtel och vitaminer.

    1 895 krMed prenumeration (årlig hälsokontroll): 1 516 kr

    See the test

  • Hjärtkollen

    22 markers

    Blodfetter, ApoB och blodsocker för att bedöma risk för hjärt-kärlsjukdom.

    499 krMed prenumeration (årlig hälsokontroll): 399 kr

    See the test

  • Lagsport

    16 markers

    För lagidrottare – energi, järn, återhämtning och stresshormon.

    1 599 krMed prenumeration (årlig hälsokontroll): 1 279 kr

    See the test

  • Kampsport

    15 markers

    För kampsportare – återhämtning, hormoner, inflammation och järn.

    1 599 krMed prenumeration (årlig hälsokontroll): 1 279 kr

    See the test

  • Hårkollen

    13 markers

    Markörer kopplade till håravfall: järn, zink, D-vitamin, B12 och hormoner.

    1 099 krMed prenumeration (årlig hälsokontroll): 879 kr

    See the test

  • Mag- och tarmkollen

    13 markers

    Kalprotektin, glutenantikroppar och näringsstatus vid magbesvär.

    1 199 krMed prenumeration (årlig hälsokontroll): 959 kr

    See the test

  • Reumatismkollen

    10 markers

    RF, anti-CCP och CRP vid ledvärk och stelhet.

    1 199 krMed prenumeration (årlig hälsokontroll): 959 kr

    See the test

  • Stresskollen

    5 markers

    Kortisol och basmarkörer vid långvarig stress, sömnbrist eller utmattningskänsla.

    599 krMed prenumeration (årlig hälsokontroll): 479 kr

    See the test

Unsure which test you need? Start the test guide

Guides covering CRP

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Responsible for the content: Mathias Khemiri, Oftamed Sverige AB.

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