Inflammation markers too high: causes and what to do next

Your result says your inflammation marker is too high, and your first question is immediately the hardest: where is it coming from? This test does not answer that. CRP is a smoke alarm. It goes off, but it does not point to a room.

The size of the number does help. A CRP of 8 tells a very different story from a CRP of 120, and that distinction is exactly what most results fail to explain.

What does a raised inflammation marker mean?

A raised CRP means your liver is making extra inflammatory protein, usually because your immune system is working somewhere. The value climbs within six to eight hours of a trigger and falls once that trigger disappears (PMID 12813013). It measures activity, not disease.

Most Dutch labs set the upper limit around 5 mg/l. What a value above that makes likely depends heavily on how far above it sits.

Read this table as a direction, not a diagnosis. Plenty of people with a CRP of 60 are back to full health within a week, and plenty with a CRP of 6 have something smouldering.

What are the most common causes?

By far the most common cause is the dullest one: an infection you had already noticed. A cold, a bladder infection, an inflamed tooth. Your immune system is doing exactly what it should, and your blood shows it.

These also come up regularly:

• A viral infection, where CRP usually stays mildly raised.
• An autoimmune disease, where sedimentation often rises more than CRP.
• Excess weight, which produces mild, persistent inflammation from fat tissue.
• A recent operation, injury or heavy training week.
• Smoking, which lifts your average value slightly but structurally.

That list explains most results. But in women there are two distortions worth knowing separately.

Which two things skew your result?

The first is hormonal contraception. Oestrogen prompts your liver to produce extra CRP, and that is not inflammation. In healthy young women on the pill, CRP averaged twice that of non-users: 2.0 versus 0.9 mg/l (PMID 12850240). That can push you over a threshold without anything being wrong.

The second is anaemia, which skews not your CRP but your ESR. Fewer red blood cells sink faster, so your sedimentation climbs while there is no inflammation. In women with heavy periods that is a real and frequently missed explanation.

Imagine a woman of 29 with a CRP of 6 mg/l and an ESR of 30 mm/hour, alarmed by her result. She is on the pill and has a ferritin of 9. Both values are explainable, and neither points to the disease she was afraid of.

So I always note two things with a raised result: are you using contraception, and how is your iron. What a low iron does sits under the ferritin value and what a low ferritin means.

Can a high inflammation marker say anything about your heart?

For that question doctors use hsCRP rather than ordinary CRP, a more sensitive version that measures low values accurately. In a study of 28,263 postmenopausal women, hsCRP was the strongest single predictor of cardiovascular events, with more than four times the risk in the highest group compared with the lowest (PMID 10733371).

There is one hard condition attached. hsCRP is only usable when you have no infection at that moment, because a common cold drowns out the signal entirely. And if you are on the pill, you are partly measuring your pill. How that fits together sits in the overview on what CRP and ESR mean.

When do you take a high inflammation marker to your GP?

Discuss your result with your GP if the value stays high on a repeat test, if you have symptoms that persist, or if fever, unintended weight loss or joint complaints come with it. A single mildly raised value without symptoms is usually not an alarm.

Thuisarts and the NHG stress that CRP is an aid in judging severity, and never a diagnosis on its own. Your GP weighs the number against your story, and that is exactly the right order.

To follow your own values, you can pick CRP and ESR together through building your own blood test. Wait until you have been symptom-free for at least two weeks, or you will be measuring your cold rather than yourself.

References

1. Pepys MB, Hirschfield GM. C-reactive protein: a critical update. J Clin Invest. 2003;111(12):1805-1812. PMID 12813013.
2. Dreon DM, Slavin JL, Phinney SD. Oral contraceptive use and increased plasma concentration of C-reactive protein. Life Sci. 2003;73(10):1245-1252. PMID 12850240.
3. Ridker PM, Hennekens CH, Buring JE, Rifai N. C-reactive protein and other markers of inflammation in the prediction of cardiovascular disease in women. N Engl J Med. 2000;342(12):836-843. PMID 10733371.
4. NHG and Thuisarts. Information on inflammation markers and blood testing. Available via thuisarts.nl.

Every blood test result at Lunara includes a professional assessment by a BIG-registered doctor. For treatment decisions, discuss your results with your GP.