Chronic low-grade inflammation tends to increase with age. Monitoring CRP supports awareness and management of inflammation-related health risks in later life.
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Check your own valueYour CRP value reflects the amount of C-reactive protein in your blood. The liver produces this protein on a signal from fat tissue. After inflammation begins, the amount of CRP rises sharply within 6 to 8 hours. What stays in the blood when you are not ill is the key question here.
CRP is a protein the liver produces on a signal from interleukin-6. For anyone working on their weight, where that signal comes from is the most interesting part.
Fat tissue is not a storage space that sits idle. It is metabolically active and produces interleukin-6 continuously. The more fat tissue, the more of that signal travels permanently to the liver. Fat around the organs in the abdomen counts most.
As a result your CRP can be mildly raised with no infection or inflammation anywhere. What you are measuring then is not a disease, but the amount of active fat tissue.
The full name is C-reactive protein, shortened to CRP. A CRP test looks at this protein alone. With acute inflammation the value rises within 6 to 8 hours. Bacterial infections give the biggest spikes, drowning out any weight effect.
That makes CRP one of the few blood values that moves with weight loss. That is precisely why it sits in this panel.
The direction is consistent. As the amount of fat tissue falls, interleukin-6 production falls. Hepatic CRP production comes down with it.
The effect is clearest with a reduction in abdominal fat, not with weight loss in general. Two people losing the same number of kilos can therefore show quite different changes in their CRP.
The change is also slow. Where CRP responds within days to an infection, here you are talking about months. A measurement every month adds little; two measurements six months apart do show something.
Important to know. A falling CRP is not proof that an approach is working. An unchanged CRP is not proof that it is not.
It is one signal alongside weight, waist circumference, blood pressure and your blood sugar. For gauging cardiovascular risk in the low range, the more sensitive hs-CRP assay exists.
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.
The change you want to see is slow. So it matters that a measurement is not contaminated by something short-lived. An infection or a hard session lifts the value sharply. Far above the level at which you wanted to read a trend.
So draw in a period when you feel well. At least two weeks after an infection. And several days after unusually hard exertion.
| Moment | What to expect from it |
|---|---|
| At the start of a programme | a baseline to compare against later |
| After 6 months | a meaningful comparison if abdominal fat has come off |
| Every month | little, the change is too slow |
| During an infection | unusable for this purpose |
| Shortly after hard exertion | unusable for this purpose |
Preferably have the value run in the same panel as your blood sugar and your lipids, so you view the whole picture in context rather than following one number.
A CRP measurement is used to confirm or exclude inflammation. Acute inflammation drowns out any pattern that has to do with weight. The same holds for a flare of an autoimmune disease.
There are two CRP tests, and the difference sits in the low range. To establish a change, compare two measurements taken under the same conditions.
If your CRP is raised, look first for an acute cause. The normal range is printed on your own result. Which upper limit your lab uses varies.
A low value is normal, causes no symptoms and never needs treating. In this panel it is the outcome you are working toward.
Two things to know. Reliable reading stops at about 5 mg/L on the routine assay. A result of less than 5 marks the floor of the test.
It is not a fine measurement. To follow a change over time in that range, the hs-CRP assay is what it is for.
A normal CRP does not rule out an infection either. Certainly not in the first hours. The rise has not started yet.
A mildly raised value causes no symptoms and does not on its own mean you are ill.
With a larger amount of fat tissue, a value sitting slightly above the limit is not odd. It is a known and expected pattern. That is not a diagnosis and not a cause for alarm. It describes the biology of metabolically active fat tissue.
A markedly raised value is a different matter. There an acute cause is likely. An infection, an infected tooth, a vaccination, an operation or a substantial bruise in the preceding days. Those explanations belong to be worked through first.
Does the value stay high while you feel well? Does none of those fit? Talk to your GP.
If you also notice fatigue, look at your ferritin as well. Inflammation lifts ferritin and can mask an iron deficiency. Those two values belong together.
Normal CRP indicates low inflammation. Maintain healthy lifestyle habits.
Elevated CRP indicates inflammation or infection. Consider anti-inflammatory diet, exercise, and evaluation for underlying conditions.
Normal CRP indicates low inflammation. Maintain healthy lifestyle habits.
Elevated CRP indicates inflammation or infection. Consider anti-inflammatory diet, exercise, and evaluation for underlying conditions.
Aim not at the number but at what sits underneath it. Here that is exceptionally amenable to change.
The strongest factor is a reduction in abdominal fat. Visceral fat is the source of the interleukin-6 signal. That is exactly where a change carries through most into your CRP. Weight alone says less about this than your waist circumference does.
Regular moderate exercise lowers the level in the long run. One hard session lifts it temporarily, so do not confuse the two when reading an isolated result.
Stopping smoking works in the same direction, and sleep counts for more than most people expect. Untreated sleep apnoea keeps the value high while nothing else is findable. It is relatively common at a higher weight.
Do not expect quick movement. This is a value you judge across months rather than weeks. Read it alongside your other results rather than on its own.
Fat tissue produces interleukin-6 continuously, which keeps hepatic CRP production permanently a little higher. With a larger amount of fat tissue a mildly raised value is a known pattern. It is not a disease.
The direction is consistent. The effect depends mainly on losing abdominal fat rather than kilos in general. Two people losing the same amount can show quite different changes.
In months, not weeks. Testing monthly adds little. Two measurements six months apart do show something, provided both were drawn in a symptom-free period.
No. It is one signal alongside your weight, waist circumference, blood pressure and blood sugar. Conversely, an unchanged value is not proof that nothing is happening.
Because the number alone points to no location and no cause. Together with your blood sugar and lipids it tells you more. As an isolated figure it says less.
Yes, and that is a known limit of the routine assay. It is built to pick up acute inflammation and does not read the low range finely. Low-grade inflammation sits in exactly that low range. If you want to know about it, the sensitive hs-CRP assay is the test to use.
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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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