INF 5 values Updated Apr 29, 2026

Inflammation Markers

Inflammation panels measure two proteins that rise when the body has an active inflammatory process: C-reactive protein (CRP) and the erythrocyte sedimentation rate (ESR). Some labs also include the high-sensitivity version (hs-CRP), which uses much finer increments and is read differently from standard CRP. These markers don't identify a cause — they describe activity. BloodSight charts every CRP and ESR you upload across visits, so the trajectory is visible alongside individual readings.

Read the Inflammation Markers guide

What Inflammation Panels Pick Up

An inflammation panel reports markers that rise when an inflammatory process is active in the body. CRP responds within hours and falls back within days; ESR moves on a slower timescale of days to weeks. Because the two markers move on different timelines, they describe slightly different windows of the same underlying process — which is why both are often ordered together. Inflammation markers describe activity, not a cause: an elevated CRP doesn't say what's driving the inflammation, only that something is.

Reasons for Checking Inflammation Markers

Inflammation panels are commonly ordered when an active inflammatory or infectious process is suspected, when an autoimmune condition is being followed, or as part of cardiovascular-risk workups (where hs-CRP specifically is informative). They're also used to track response to treatment — a falling CRP across consecutive panels is one of the clearer signals that an inflammatory process is calming.

Markers in an Inflammation Panel

The standard inflammation panel reports two values: CRP and ESR. CRP is reported on a coarser scale (often <3 mg/L = normal), while hs-CRP — sometimes ordered alongside or instead — uses finer increments and reports values in tenths of mg/L. ESR is reported in millimetres per hour and depends on sex and age in its reference cutoffs. Some panels also include fibrinogen, ferritin (which doubles as an iron-status marker), and homocysteine.

Reading CRP, hs-CRP, and ESR Together

Inflammation markers describe activity, not cause — an elevated CRP signals an inflammatory process is happening but doesn't identify what's driving it. Reading the markers together with the timeline of any recent illness, surgery, or training stress is what makes the panel interpretable.

  1. 1

    CRP vs hs-CRP

    Standard CRP and high-sensitivity CRP measure the same protein but at different sensitivity levels. Standard CRP is reported on a coarser scale (often <3 mg/L = normal) and is used to assess overt inflammation. hs-CRP uses much finer increments (often <1.0 mg/L = low cardiovascular risk) and is used to assess low-grade background inflammation, often in cardiovascular workups.

  2. 2

    ESR — the slower-moving marker

    ESR (erythrocyte sedimentation rate) rises and falls more slowly than CRP — over days to weeks rather than hours to days. ESR varies with sex and age, with widening reference ranges in older adults. ESR captures longer-window inflammation than CRP.

  3. 3

    CRP and ESR together

    Both markers elevated together typically describes active ongoing inflammation. CRP elevated with normal ESR can describe a recent fast-onset trigger. ESR elevated with low CRP is less common and is read in clinical context.

  4. 4

    Acute vs chronic patterns

    A single elevated CRP can describe almost anything — a recent infection, a heavy training session, recent surgery, an autoimmune flare. Persistent CRP elevation across multiple panels carries different weight than a one-off spike.

  5. 5

    Context matters

    Inflammation markers are most informative read alongside clinical context. The interpretation depends heavily on what else is going on at the time of the draw — recent illness, recent surgery, recent training, autoimmune activity, or persistent low-grade inflammation related to body composition or smoking.

Read the full Inflammation Markers guide

Inflammation Marker Reference Ranges

Standard CRP is reported on a coarser scale (often <3 mg/L = normal) while hs-CRP uses much finer increments — these are different tests despite the similar names. ESR is reported in millimetres per hour and varies by sex and age. The ranges below describe the typical adult cutoffs.

Test Normal range (Adult) Unit Flagged when
C-Reactive Protein CRP 0–3 mg/L < 0 or > 3
High-Sensitivity C-Reactive Protein hs-CRP 0–3 mg/L < 0 or > 3
Erythrocyte Sedimentation Rate ESR 0–15 mm/hr < 0 or > 15
Procalcitonin PCT 0–0.05 ng/mL < 0 or > 0.05
Serum Amyloid A SAA 0–10 mg/L < 0 or > 10

What Drives Inflammation Marker Values

Inflammation markers rise during infections, recent surgery or injury, autoimmune flares, and chronic low-grade inflammation related to body composition or smoking. CRP responds within hours; ESR moves over days, which is why both are often ordered together.

Common factors for high values

Common factors for low values

Every Inflammation Marker

C-Reactive Protein

CRP

C-Reactive Protein (CRP) is a blood protein made by the liver that rises when the body is responding to inflammation. On a blood test or lab report, CRP helps show how much of this protein is present in the sample and how that result compares with the CRP normal range. It is often reviewed with other markers to build a broader picture of current blood chemistry.

Adult Male mg/L
0
3

High-Sensitivity C-Reactive Protein

hs-CRP

High-Sensitivity C-Reactive Protein (hs-CRP) is a blood marker that reflects inflammation-related changes in the body. It is measured from a blood test and often appears on an inflammation panel, where it helps show how much hs-CRP is present in the sample. The hs-CRP result is usually reviewed with other markers and with the High-Sensitivity C-Reactive Protein normal range to understand whether the value is low, typical, or high.

Adult Male mg/L
0
3

Erythrocyte Sedimentation Rate

ESR

Erythrocyte Sedimentation Rate (ESR) is a blood test value that measures how fast red blood cells settle in a tube over time. It is often used as a broad marker of changes in blood composition and is commonly listed on an ESR on a blood test or Erythrocyte Sedimentation Rate on a lab report. ESR is usually interpreted together with other lab values, since the result can shift with hydration, age, sex, and other non-specific factors.

Adult Male mm/hr
0
15

Procalcitonin

PCT

Procalcitonin (PCT) is a lab marker measured in blood and often reported on an inflammation-focused panel. It reflects how much of this protein is circulating in the blood, and Procalcitonin on a lab report can help describe whether the result is within the Procalcitonin normal range, high PCT, or low PCT.

Adult Male ng/mL
0
0.05

Serum Amyloid A

SAA

Serum Amyloid A (SAA) is a blood protein that rises and falls in response to inflammation-related signals. On a lab report or blood test, SAA helps describe how strongly the body is responding at a given moment. It is commonly listed in inflammation-focused panels and is usually read alongside other markers that help show the broader blood picture.

Adult Male mg/L
0
10

Compare values in this panel

How values in this panel relate to each other and what their differences mean.

Preparing for an Inflammation Panel

Inflammation markers do not require fasting. The single most important preparation note is timing: a recent acute illness, recent surgery, or even a heavy training session can transiently raise CRP for days. If the goal is to assess background inflammation rather than acute response, the panel is usually drawn well away from those events.

Inflammation Panel FAQ

What does an inflammation panel measure?
An inflammation panel measures markers that rise when an inflammatory process is active in the body — most commonly C-reactive protein (CRP) and the erythrocyte sedimentation rate (ESR). Some panels also include hs-CRP (a finer-grained version of CRP), homocysteine, or fibrinogen. These markers describe activity, not a cause: an elevated value indicates that an inflammatory process is happening, but does not identify what is driving it.
What does a high CRP result mean?
An elevated CRP means an inflammatory process is active in the body — that could be an infection, recent injury, autoimmune activity, post-surgery healing, or chronic low-grade inflammation. CRP itself does not tell you which one. The pattern of CRP across multiple panels usually carries more interpretive weight than any single elevated value, and the surrounding clinical context determines what an elevated CRP is actually describing.
What's the difference between CRP and hs-CRP?
They measure the same protein but at different sensitivity levels. Standard CRP is reported on a coarser scale (often <3 mg/L = normal) and is used to assess overt inflammation. High-sensitivity CRP (hs-CRP) reports much finer increments — often in tenths of mg/L — and is used to assess low-grade background inflammation, frequently in cardiovascular-risk workups. They use different reporting cutoffs and are not directly comparable.
What's the difference between CRP and ESR?
Both rise during inflammation, but on different timelines. CRP changes fast — rising within hours of an inflammatory trigger and falling within days when the trigger resolves. ESR moves more slowly, both rising and falling over days to weeks. Many panels include both because they describe different windows of the same process: CRP captures what's happening now; ESR captures the trend over a longer recent period.
What causes high inflammation markers?
Inflammation markers like CRP and ESR rise in response to many processes — infections (viral or bacterial), autoimmune activity, recent surgery or trauma, chronic low-grade inflammation tied to body composition or smoking, and even intense recent exercise. The specific cause isn't read from the inflammation marker alone; the surrounding clinical context, recent history, and other lab values determine interpretation.
What are normal ranges for CRP and ESR?
Standard CRP is typically reported as normal below ~3 mg/L; some labs use <5 or <10 mg/L cutoffs. High-sensitivity CRP (hs-CRP) uses much finer increments, with <1.0 mg/L often described as low cardiovascular risk and >3 mg/L as elevated. ESR is reported in millimetres per hour and varies by sex and age — typical adult ranges are roughly 0–22 mm/hr for men and 0–29 mm/hr for women, with ranges widening with age.
Is mildly elevated CRP dangerous?
A single mildly elevated CRP describes inflammation in that moment — often acute and self-limiting, like a recent infection, intense workout, or short-term illness. Persistently elevated CRP across multiple panels is generally followed up by an ordering provider because it suggests ongoing rather than transient inflammation. Pattern across multiple readings carries more interpretive weight than any single elevated value.
Do I need to fast for an inflammation panel?
CRP and ESR do not typically require fasting. The single most important preparation note is timing: recent acute illness, recent surgery, or even a heavy training session can transiently raise CRP for days. If the goal is to assess background inflammation rather than acute response, the panel is usually drawn well away from those events.
How long do inflammation panel results take?
CRP and ESR results are typically returned within 1–2 business days. Patient portals usually post values first; the full PDF often follows shortly after. Hospital and same-day clinic settings can return CRP within hours.
How does BloodSight track inflammation over time?
BloodSight charts every CRP, ESR, and other inflammation marker value across all your uploaded panels in one timeline. Inflammation markers are most informative as a trajectory — rising, falling, or stable — rather than as a single reading, so seeing every value side by side makes the pattern obvious in a way that flipping through individual lab reports often doesn't.

Panels That Often Pair With Inflammation Markers

Inflammation markers are read alongside the panels that describe what the immune system is responding to. The panels below most often share the same draw or follow-up workflow during an inflammatory or anemia-of-inflammation workup.

CBC

Complete Blood Count (CBC)
AUT

Autoimmune Panel
FE

Iron Studies

Disclaimer

This content is for informational and educational purposes only. It is not intended as medical advice, diagnosis, or treatment recommendation. Reference ranges may vary by laboratory. Always discuss your results with a qualified healthcare professional.