Maybe a number on your lab report came back flagged, or you've seen an at home inflammation test and wondered whether it's worth doing. Inflammatory markers are among the most widely used blood tests, because they tell a clinician quickly whether something in your body has set off an immune response. What they can't do is tell you what that something is, and that's the part most people don't hear when the result comes back.
What are inflammatory markers?
Inflammatory markers are substances in your blood that rise when your immune system is responding to infection, injury or ongoing irritation. The most common one, C-reactive protein (CRP), is made by the liver in response to signals from immune cells, and because it's cleared at a steady rate, its level reflects how much inflammation is happening right now (Pepys, 2003). The others each capture a slightly different part of the picture, which is why clinicians often order more than one.
| Marker | What it measures | Typical use | Limits |
|---|---|---|---|
| CRP | A liver protein that rises within hours of inflammation | Checking for infection or active inflammation, and tracking it over time | Doesn't show where inflammation is or why |
| hs-CRP | The same protein, measured precisely at low levels | Estimating cardiovascular risk in people without acute illness | Needs two readings when you're well, and any recent infection skews it |
| ESR (sed rate) | How fast red blood cells settle in a tube | Monitoring some chronic inflammatory conditions | Rises and falls slowly, and often disagrees with CRP |
| Ferritin | The body's iron storage protein | Checking iron stores | Also rises with inflammation, which can hide low iron |
| Fibrinogen | A clotting protein that rises with inflammation | Clotting assessment, sometimes heart risk research | Not recommended over hs-CRP for routine risk checks |
| White blood cell count | The number of immune cells in the blood | Part of a routine blood count, flags infection | Changes with many conditions and medications |
Other markers, like the immune signal interleukin 6, are mostly used in research rather than routine care (Pearson, 2003).
Why a high result doesn't tell you the cause
Inflammatory markers are non-specific, which means many different things push them up in the same way. A cold, a dental infection, a sprained ankle or a flare of an autoimmune condition can all raise CRP (Pepys, 2003), and so can everyday factors that have nothing to do with disease.
A hard bout of exercise produces a short rise in inflammatory markers, even though regular training lowers them over time (Kasapis, 2005). Excess body fat is linked with persistently higher CRP (Visser, 1999), and disturbed sleep is associated with higher CRP and interleukin 6 (Irwin, 2016). That's why ESR and CRP are meant to be read alongside your history and a physical exam rather than on their own, and why the two markers often disagree with each other (Bray, 2016).
What hs-CRP numbers mean for heart health
High-sensitivity CRP is the one inflammation test with agreed cutoffs, and those cutoffs are about cardiovascular risk rather than inflammation in general. A 2003 statement from the American Heart Association and the CDC set three bands: under 1 mg/L is lower risk, 1 to 3 mg/L is average risk, and above 3 mg/L is higher risk (Pearson, 2003).
The same statement recommended taking two measurements about two weeks apart, when you're well, and averaging them. It also said a result above 10 mg/L should be repeated and followed by a look for an infection or inflammatory source, because at that level something other than heart risk is usually driving the number (Pearson, 2003). It's a tool for refining risk alongside blood pressure, cholesterol and your history, not a standalone test.
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Explore the inflammation programCan you have inflammation without symptoms?
Yes, and that's the kind of inflammation hs-CRP is built to pick up. Low-grade inflammation doesn't cause the heat, swelling and pain of an injury, so you won't feel it, but it can show up as a mildly raised CRP that stays that way over time.
It's also common. In a large US national survey, more than a quarter of adults had CRP at a level the researchers classed as elevated, with higher rates in people carrying more body fat (Visser, 1999). A persistently raised reading is worth taking seriously, and since it doesn't point to its own cause, the next step is working out what's feeding it, whether that's weight, sleep, chronic stress, a gut problem or something that needs its own workup.
Are at home inflammation tests accurate?
An at home inflammation test can measure CRP reasonably well, but it can't do the interpreting for you. Most use a finger prick and a dried blood spot mailed to a lab, and researchers have shown that high-sensitivity CRP can be measured from dried blood spots when the sample is collected and handled properly (McDade, 2004).
The limits are the same ones any CRP test has, only without a clinician in the room. A single reading taken during a cold or the day after a hard workout can look alarming, one normal reading doesn't rule out a problem, and a kit can't tell you whether the source is your gums, your gut or your joints. If you use one, treat the result as something to bring to a clinician rather than a diagnosis.
What a clinician does with an elevated result
A clinician starts by asking whether the number is real and lasting, then looks for what's behind it. That usually means repeating the test once you're well, reviewing recent illness, injuries, medications and exercise, and examining you for a source.
Common next steps include:
- Repeating CRP or hs-CRP a couple of weeks later to see whether it's persistent
- Checking related markers together, like ESR, ferritin and a complete blood count
- Looking for infection, autoimmune or gut conditions that match your symptoms
- Reviewing weight, sleep, stress and activity, which all shift these markers
- Putting hs-CRP in context with blood pressure and cholesterol for heart risk
How Ivologist's chronic inflammation program approaches this
Ivologist's Health and Chronic Inflammation Program starts with a clinician-led evaluation: a full medical intake, a review of your symptoms and history, and diagnostic labs as clinically indicated, followed by a provider consultation once the results are in. From there, the plan is built around what the evaluation finds, with health coaching and ongoing clinician oversight rather than a single fixed protocol. If the evaluation points toward the gut, the Gut and Autoimmune Health Program takes that route in more depth.
Frequently Asked Questions
Where to go from here
Inflammatory markers are good at telling you that something's going on and much less good at telling you what, so an elevated result is worth following up with someone who can look for the cause. A result is where the question starts, and the useful work happens after it.
Book a discovery call for the Health and Chronic Inflammation Program and a licensed clinician will review your labs and history before recommending next steps.
Medical disclaimer. This article is for informational purposes only and doesn't constitute medical advice. An elevated inflammatory marker can signal an infection or condition that needs prompt care, so talk to your clinician about any abnormal result, and seek urgent care for fever, chest pain or severe symptoms. Results vary. Always consult a qualified healthcare provider before starting, changing, or stopping any treatment.
