CRP and weight: how baseline CRP relates to BMI and weight loss
CRP, in full C-reactive protein, is a protein that the liver makes and releases into the bloodstream, and that according to the NVKC rises sharply within 6 to 8 hours in an inflammation. Even without inflammation, a small amount is in the blood: the baseline CRP.
According to a 2003 review, a higher BMI goes together with a higher baseline CRP. According to the NVKC, CRP can rise by a factor of 1000 in an inflammation. A blood test is the only way to see how high CRP is.
Unilabs gives 0 to 5 mg/l as the reference values for CRP.
Doctor's Assessment Included
CRP is a protein made by the liver that rises sharply in the blood within 6 to 8 hours of the start of an inflammation. The upper limit differs by laboratory: 5 mg/l at Unilabs and Certe, 6 at Diagnostiek voor U and 10 at Star-SHL.
- A raised CRP can point to an inflammation or infection, but does not show where it is or what causes it.
- Once an inflammation subsides, CRP can fall quickly: its half-life is about 19 hours, which makes recovery easy to follow with CRP.
- A normal CRP does not rule out an infection that has just started, because CRP only rises above 5 mg/l about 6 hours after an inflammation begins.
Reference Ranges
See the value that applies to you:
Choose male or female — this range differs by sex.
Enter your age — this range changes with age.
This range also depends on context such as cycle phase or sample material; the highlighted rows apply to your group.
Reference ranges may vary between laboratories. When you order a test, a BIG-registered doctor assesses your personal results in context. For treatment decisions, discuss your results with your GP.
Check your own valueCRP (C-Reactive Protein): what Dutch laboratories use
The upper limit runs from 5 mg/l at Unilabs to 10 mg/l at Star-shl.
| Laboratory | Group | Reference value (mg/l) | Relative scale |
|---|---|---|---|
| Star-shl | · Everyone | 0–10 mg/l |
0 10
|
| Unilabs | · Everyone | 0–5 mg/l |
0 5
|
| Certe | · Everyone · 18 years and older · a limit, not a range | < 5 mg/L |
5
|
| Diagnostiek voor U | · Everyone · a limit, not a range | < 6 mg/L |
6
|
Source: Star-shl
Source: Unilabs
Source: Certe
Source: Diagnostiek voor U
Each value as the laboratory itself publishes it, retrieved in 2026.
CRP (C-Reactive Protein): what this test measures
The CRP test measures C-reactive protein in the blood in mg/l, and according to the NVKC only the more sensitive hs-CRP test measures the very small amounts the body makes over a long time in cardiovascular disease.
CRP (C-Reactive Protein): why this value matters
According to a 2003 review, a raised baseline CRP is associated with many features of insulin resistance and the metabolic syndrome, up to and including diabetes.
CRP (C-Reactive Protein): how the blood test works
- Referral
- No GP referral needed. After the order we arrange the referral through ZorgDomein, within one business day; orders after 17:00 or at the weekend start on the next business day. ZorgDomein emails a barcode, and that barcode is what the draw site needs.
- The draw
- A blood draw from a vein in the arm, at a partner laboratory's draw site. No home kit, no finger prick.
- Where
- 650+ draw sites run by independent laboratories across the Netherlands. Draw sites
CRP (C-Reactive Protein): how to prepare
-
Been ill? Wait a little
RequiredHad a fever, an infection or a vaccination in the past 2 weeks? Wait with the draw until you are fully recovered. These values react to inflammation and would give a distorted picture.
-
Better no hard training beforehand
RecommendedHard exercise in the 48 hours before can raise this value temporarily. Plan the draw on a rest day if you can.
- Water is always fine. Drink as usual beforehand, it makes the draw easier.
- Take your usual medication, unless your own doctor told you otherwise.
CRP (C-Reactive Protein): when is testing worthwhile?
According to the NVKC, a CRP test is used among other things to find out whether there may be inflammation, for example in the abdomen.
CRP (C-Reactive Protein): symptoms of a high or low value
Low Levels
According to a 2003 review, a lower baseline CRP goes together with physical exercise, and Unilabs gives a lower limit of 0 mg/l for CRP.
High Levels
According to the NVKC, an acute inflammation is one possible explanation for a raised CRP, and according to a 2018 review some bacterial infections can raise CRP up to 1,000-fold.
CRP (C-Reactive Protein): causes of a low or high value
What lowers the value
-
Liver failure
The liver makes CRP, and in liver failure less CRP is produced.
-
Statins
Statins, cholesterol-lowering medicines, lower CRP, separately from their effect on cholesterol.
What raises the value
-
Infection or acute inflammation
A raised or rising CRP can point to acute inflammation or infection.
-
Dead tissue
Dead tissue is a strong trigger for CRP; a heart attack is followed by a large CRP response.
-
Chronic inflammatory disease
In some people with a chronic inflammatory disease such as rheumatoid arthritis, CRP stays raised; lupus (SLE), an autoimmune disease, does not cause a large CRP rise despite clear inflammation.
-
Overweight
A higher BMI goes with a higher baseline CRP, the CRP value without inflammation, and weight loss lowers it.
-
The pill and hormone tablets
The contraceptive pill and hormone therapy taken as tablets after menopause go with a higher CRP without inflammation; hormone therapy through the skin does not.
CRP (C-Reactive Protein): lifestyle and this value
With a higher BMI, which according to a 2003 review goes together with a higher baseline CRP, weight loss lowers the CRP value according to that review. Talk to your GP about a raised CRP.
CRP (C-Reactive Protein): frequently asked questions
Does eating affect CRP during an acute inflammation?
No, according to a 2003 review, CRP values in an acute inflammatory response do not depend on eating and show no variation over the day.
CRP (C-Reactive Protein): sources
- Star-shl, Labbepalingen (referentiewaarden per bepaling), star-shl.nl, geraadpleegd 2026-10-01 (retrieved 2026) star-shl.nl
- Unilabs, Bepalingenklapper (referentiewaarden per bepaling), bepalingenklapper.nl, geraadpleegd 2026-10-01 (retrieved 2026) bepalingenklapper.nl
- Certe, Bepalingenwijzer (referentiewaarden per bepaling), bepalingenwijzer.certe.nl, geraadpleegd 2026-10-01 (retrieved 2026) bepalingenwijzer.certe.nl
- Diagnostiek voor U, eLabgids (Referentiewaarden DvU), diagnostiek.getincontrol.eu, geraadpleegd 2026-10-01 (retrieved 2026) diagnostiek.getincontrol.eu
- Pepys MB, Hirschfield GM. C-reactive protein: a critical update. J Clin Invest 2003;111(12):1805-1812. (retrieved 2026) pmc.ncbi.nlm.nih.gov
- NVKC, Alles over testen: CRP, allesovertesten.nl, geraadpleegd 2026-10-06 (retrieved 2026) allesovertesten.nl
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Every result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.
CRP (C-Reactive Protein)
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