hs-CRP vs CRP: what is the difference?
Updated October 31, 2026 · 7 sources · Written by the AumniVIDA team
UnitsShort answer
hs-CRP and CRP measure the same protein. A standard CRP test is built for infection and inflammation and usually cannot read below about 3 mg/L; an hs-CRP test reads down to about 0.1 mg/L, the range that matters for heart risk. There is no conversion between them; only mg/dL to mg/L (multiply by 10).
Key takeaways
What is the difference between hs-CRP and CRP?
The molecule is the same; the measuring range is different. Standard CRP tests answer whether there is active infection or inflammation, while hs-CRP tests measure the low-grade levels used to judge heart risk in people who are well.
CRP can range from under 0.05 mg/L in health to over 500 mg/L in severe infection [4]. No single assay is equally precise across that whole span.
- Standard CRP is tuned for the high range seen in infection, inflammatory disease and after surgery. It is used to detect these conditions and track treatment.
- hs-CRP is tuned for the low range. It is used in metabolically stable people to sort heart risk into the under 1, 1 to 3 and over 3 mg/L groups [3].
So an hs-CRP of 0.4 mg/L and a standard CRP reported as "under 5" can describe the same blood sample. The second simply cannot say how far below 5 it is.
What range does each test measure?
A typical standard CRP assay detects from about 3 mg/L upward; a typical hs assay detects from about 0.1 mg/L, with some reaching 0.01 mg/L. hs assays stay precise, with under 10% error, from 0.3 to 10 mg/L.
| Feature | Standard CRP | hs-CRP | Source |
|---|---|---|---|
| Lowest reliable value | About 3 mg/L (0.3 mg/dL) | About 0.1 mg/L (0.01 mg/dL) or lower | [1] [2] |
| Precise working range | Up into the hundreds of mg/L | 0.3 to 10 mg/L with under 10% error | [3] |
| Main use | Infection, inflammatory disease, monitoring | Heart and stroke risk in people who are well | [3] |
| Values that matter | Usually over 10 mg/L | Under 1, 1 to 3, over 3 mg/L | [2] [3] |
Exact limits vary by laboratory and manufacturer, so your report's own reference range is the final word.
How do you convert hs-CRP to CRP?
You do not need to. hs-CRP and CRP are the same quantity in the same units, so a value of 15 mg/L means the same on either test. The only conversion is between units: mg/L equals mg/dL times 10.
Because both tests measure the same molecule, there is no conversion factor between them. In 840 people starting dialysis, whose CRP both methods could measure, the two agreed closely (intraclass correlation 0.86 after correcting for small systematic differences) [1].
Units are where most confusion arises. The CDC/AHA statement asked labs to report hs-CRP in mg/L only [3], but some still print mg/dL.
| mg/L | mg/dL | What it means for heart risk |
|---|---|---|
| 0.5 | 0.05 | Lower relative risk |
| 1.0 | 0.10 | Boundary of lower and average |
| 2.0 | 0.20 | Risk-enhancing factor [5] |
| 3.0 | 0.30 | Boundary of average and higher |
| 10 | 1.0 | Repeat and look for a cause |
| 50 | 5.0 | Acute inflammation range |
When is each test used?
Doctors order standard CRP when they suspect infection or inflammatory disease, or to follow treatment. They order hs-CRP to refine heart risk in someone who is well, usually alongside cholesterol tests.
The CDC/AHA statement recommended hs-CRP for people at intermediate risk, a 10% to 20% chance of coronary disease over 10 years, at the clinician's discretion, and advised against screening the whole adult population [3]. The 2018 AHA/ACC guideline uses an hs-CRP of 2 mg/L or more as a risk-enhancing factor [5], and the 2025 ACC statement calls for much broader testing alongside LDL cholesterol [6] [7].
In people starting dialysis for kidney failure, where CRP is often high, the high-sensitivity method added little: standard and hs methods agreed well on who had systemic inflammation over 10 mg/L and predicted mortality equally [1].
Can a standard CRP result be used for heart risk?
Only if it reports an exact value in the low range. A standard result such as "under 5 mg/L" cannot place you in the under 1, 1 to 3 or over 3 mg/L groups, so ask for an hs-CRP test instead.
The heart-risk categories depend on telling 0.8 mg/L from 2.5 mg/L. A test whose detection limit is about 3 mg/L cannot do that [1]. If your report shows a standard CRP above 10 mg/L, the same rule applies as for hs-CRP: the value reflects active inflammation, not heart risk, and should be repeated once you are well [3].
For the rest of the picture, see the hs-CRP test page and the hs-CRP hub.
More about hs-CRP
- hs-CRP: the full guidehs-CRP is a blood test that measures C-reactive protein, an inflammation protein made by the liver, at very low levels.
- What does a high hs-CRP mean?A high hs-CRP means more inflammation than average.
- How to lower hs-CRPThe biggest lifestyle lever is weight loss: about 0.13 mg/L lower hs-CRP per kilogram lost, and 29% to 44% lower in intensive lifestyle programs.
- What is a normal hs-CRP level?A normal hs-CRP for heart risk is under 3 mg/L (0.3 mg/dL), and under 1 mg/L (0.1 mg/dL) is the lowest-risk group.
- hs-CRP test: fasting, timing and what affects itThe hs-CRP test is an ordinary blood draw and does not need fasting.
Protocols that act on hs-CRP
- Anti-inflammatory dietAn anti-inflammatory diet is an eating pattern meant to lower chronic low-grade inflammation: more oily fish, olive oil, vegetables, fruit, legumes, nuts and whole grains, and less processed meat, refined carbohydrate and sugary drinks.
- Mediterranean dietThe Mediterranean diet is an eating pattern built on vegetables, fruit, legumes, whole grains, nuts, fish and olive oil as the main fat, with little red or processed meat, butter or sweets.
- Zone 2 cardioZone 2 cardio is steady aerobic exercise held just below the first lactate threshold, where blood lactate stays near 2 mmol/L and you can still talk in full sentences.
- Sleep consistencySleep consistency means going to bed and waking up at about the same times every day, weekends included.
Common questions
Is hs-CRP more accurate than CRP?
Is CRP in mg/L or mg/dL?
Guidance asks for mg/L [3], but some labs use mg/dL. Multiply mg/dL by 10 to get mg/L.
Is hs-CRP the same as cardio CRP?
Yes. Cardio CRP, cardiac CRP and high-sensitivity CRP are lab names for the same low-range CRP test used for heart risk.
Sources
- 1.Grootendorst DC, de Jager DJ, Brandenburg VM, et al. Excellent agreement between C-reactive protein measurement methods in end-stage renal disease patients--no additional power for mortality prediction with high-sensitivity CRP. Nephrology Dialysis Transplantation, 2007. doi:10.1093/ndt/gfm381
- 2.Kamath DY, Xavier D, Sigamani A, Pais P. High sensitivity C-reactive protein (hsCRP) & cardiovascular disease: An Indian perspective. Indian Journal of Medical Research, 2015. doi:10.4103/0971-5916.166582
- 3.Pearson TA, Mensah GA, Alexander RW, et al. Markers of inflammation and cardiovascular disease: application to clinical and public health practice: A statement for healthcare professionals from the Centers for Disease Control and Prevention and the American Heart Association. Circulation, 2003. doi:10.1161/01.cir.0000052939.59093.45
- 4.Pepys MB, Hirschfield GM. C-reactive protein: a critical update. Journal of Clinical Investigation, 2003. doi:10.1172/JCI18921
- 5.Grundy SM, Stone NJ, Bailey AL, et al. 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation, 2019. doi:10.1161/CIR.0000000000000625
- 6.Mensah GA, Arnold N, Prabhu SD, Ridker PM, Welty FK. Inflammation and Cardiovascular Disease: 2025 ACC Scientific Statement: A Report of the American College of Cardiology. Journal of the American College of Cardiology, 2025. doi:10.1016/j.jacc.2025.08.047
- 7.TCTMD. ACC: It's Time for Clinicians to Address Inflammation in CVD. TCTMD (Cardiovascular Research Foundation), 2025. Link