hs-CRP optimal range and reference range
Compiled by Alina Radu, founder of Sera, from the published sources below · Last reviewed November 9, 2026
Sera's bands for hs-CRP:
- Optimal 0 – 0.99 mg/L (0 – 0.099 mg/dL); sufficient 0 – 3 mg/L (0 – 0.3 mg/dL); out of range below 0 or above 3 mg/L.
Evidence grade: Established clinical threshold. A band edge that corresponds to a recognised diagnostic, risk or treatment threshold from a major clinical guideline or public-health body.
All units
| Unit | Optimal | Sufficient | Out of range |
|---|---|---|---|
| mg/L | 0 – 0.99 | 0 – 3 | below 0 or above 3 |
| mg/dL | 0 – 0.099 | 0 – 0.3 | below 0 or above 0.3 |
What the evidence says
The bands follow the American Heart Association and CDC cardiovascular risk categories: below 1 mg/L is low risk, 1 to 3 is average risk, above 3 is high risk. US cardiology guidance also treats 2 mg/L or more as a risk-enhancing factor in primary prevention, so a result in the upper part of the acceptable band is not neutral. A single raised hsCRP can reflect any recent infection or injury. Cardiovascular risk stratification requires a repeat measurement when the person is well.
Sources
- C-reactive protein — MedlinePlus Medical Encyclopedia, US National Library of Medicine, 2025 · Government / public-health guidanceCiting the American Heart Association: low cardiovascular risk when hs-CRP is lower than 1.0 mg/L, average risk from 1.0 to 3.0 mg/L, high risk above 3.0 mg/L. Matches Sera's optimal and sufficient upper edges. Reviewed 28 January 2025.
- C-Reactive Protein (CRP), High Sensitivity (test 120766) — Labcorp test directory, 2026 · Laboratory / reference-interval sourceReports hs-CRP against three risk categories: low risk below 1.00 mg/L, average risk 1.00 to 3.00, high risk above 3.00. Current directory entry, opened October 2026; it attributes the categories to the 2003 AHA/CDC statement.
- Prioritizing Health | hsCRP: A Promising Risk Assessment Tool — American College of Cardiology, Cardiology Magazine, 2025 · Professional societyStates that an hsCRP of 2 mg/L or more counts as a risk-enhancing factor in primary prevention under current guidelines. This threshold falls inside Sera's sufficient band and supports the note, not a band edge.
What hsCRP (High-Sensitivity C-Reactive Protein) measures
A sensitive marker of inflammation throughout the body.
Raised hsCRP points to long-term inflammation and tracks how well anti-inflammatory changes are working.