What Is hs-CRP, and What Does Your Result Mean?

High-sensitivity C-reactive protein (hs-CRP) is a blood test measuring a protein your liver produces when there is inflammation somewhere in the body. It is sensitive but nonspecific — it can show that inflammation is present without indicating where it is or what is causing it. A single elevated reading does not establish a diagnosis, because infection, injury and recent illness all raise it temporarily. Interpretation belongs with your doctor, in the context of everything else known about your health.

1. What the test actually measures

C-reactive protein is made by your liver in response to inflammatory signalling. When inflammation rises, CRP rises with it.

The "high-sensitivity" version measures the same protein at much lower concentrations. Standard CRP is used to detect obvious inflammation — a serious infection, an inflammatory flare. hs-CRP can resolve the low-grade range where the differences are small but potentially meaningful over years.

The critical limitation, and the one most often skipped: hs-CRP is nonspecific. It tells you inflammation is present somewhere. It cannot tell you where, or why. A chest infection, gum disease, rheumatoid arthritis, obesity, a recent injury and a hard training week can all raise it. The test does not distinguish between them.

That single fact governs how any result should be read. Anyone treating hs-CRP as a diagnosis, or as a score to be driven down for its own sake, has misunderstood what it is.

2. The risk bands you will see quoted

The categories used for cardiovascular risk stratification, and still the ones most laboratories report against:

| hs-CRP | Category |
|---|---|
| Under 1 mg/L | Lower relative risk |
| 1 to 3 mg/L | Average relative risk |
| Above 3 mg/L | Higher relative risk |

Two notes about them. These describe relative cardiovascular risk across populations, not a measure of general health. And readings above roughly 10 mg/L are generally taken to indicate an acute inflammatory process — infection, injury, a flare — rather than the baseline low-grade range these bands were designed to describe. A result in that territory usually prompts a repeat test once the acute event has resolved.

3. Where the 2 mg/L threshold comes in

You will also see 2 mg/L used as a threshold, and it is worth understanding how it differs from the bands above.

In contemporary primary prevention of atherosclerotic cardiovascular disease, hs-CRP of 2 mg/L or above is used as a risk-enhancing factor — one of a list of findings that can shift a borderline decision, most often about whether to begin statin therapy, when the overall risk estimate sits in an intermediate range.

That is a narrower thing than it may sound. It is:

• An input to a decision, not a diagnosis
• Applied in the context of an overall risk assessment, not in isolation
• Relevant to a specific clinical question, not a general verdict on health

The 2 mg/L threshold does not replace the under-1 / 1–3 / above-3 bands. They answer different questions — one stratifies population risk, the other contributes to an individual treatment decision. Neither makes 2 mg/L a universal cutoff between healthy and unhealthy.

4. Why one reading is not a verdict

hs-CRP moves. It is designed to.

Anything that raises inflammation raises it, often substantially and often temporarily:

• Infection — including a cold or a chest infection you have almost shrugged off
• Injury, recent surgery, or dental work
• Inflammatory conditions in a flare
• Other acute states, from a hard training session to poor sleep

A raised result taken during or shortly after any of these mostly reflects that event. This is why a single number is weak evidence about your long-term cardiovascular risk, and why clinicians assessing baseline inflammation typically want a repeat test some weeks later, taken when you are well.

Persistent elevation across repeated tests, when you are otherwise healthy, is a different and more meaningful finding than one high reading.

5. What to do with a result

Take it to the person who ordered it.

That is not a dodge. A number in isolation genuinely cannot be interpreted — the same 4 mg/L means something different in someone who has just recovered from flu than in someone with no recent illness, and different again alongside blood pressure, lipids, family history and everything else your doctor knows about you.

Questions worth asking:

• Was I unwell, injured or recovering when this was drawn?
• Is it worth repeating when I have been well for a few weeks?
• How does this sit with the rest of my results?
• Does it change anything you would recommend?

What this article will not do is tell you what your result means, or what to take. That is individual medical advice, and it needs someone who can see your whole picture.

Why researchers use hs-CRP, including in our own studies

Because it is objective, inexpensive, widely available, and measured on a continuous scale rather than reported by the participant. In a field where most outcomes are questionnaires, a blood marker is a useful anchor.

It is used as a marker — a measurable stand-in for something harder to observe directly. Using it as an endpoint is not the same as showing that changing it changes anything a person feels.

Both LanFam studies used hs-CRP as their primary endpoint, and neither established that the formula lowers it. The 60-day study did not meet that endpoint. The 8-week study's headline result was reported as a one-sided test whose two-sided equivalent is approximately 0.08, in twelve uncontrolled participants. Nothing here should be read as evidence that ProleevaMax lowers hs-CRP. The full account, including where the reports contradict themselves, is in inside the ProleevaMax studies.

If your own hs-CRP is elevated, the useful next step is the conversation in section 5 — not a supplement.