Is my hs-CRP (C-Reactive Protein) normal?
Free blood test checker · Standard + longevity-optimal ranges
What is a normal hs-CRP level?
High-sensitivity CRP measures systemic inflammation — a central driver of biological aging known as "inflammaging." It's one of the strongest predictors of cardiovascular events. The AHA classifies risk as: low (<1.0 mg/L), moderate (1.0-3.0), high (>3.0). Elevated hs-CRP signals an inflamed, permeable arterial endothelium, dramatically increasing the likelihood that ApoB-containing particles penetrate the intima and initiate atherosclerotic plaque formation. Chronic low-grade inflammation also accelerates neurodegeneration and cancer risk.
| Range | Values |
|---|---|
| Standard Reference | 0–1 mg/L |
| Optimal | 0–1 mg/L |
| Longevity Optimal | < 0.5 mg/L |
| High Risk | > 3 mg/L |
What causes abnormal hs-CRP levels?
Elevated hs-CRP indicates systemic inflammation, which can be caused by obesity (especially visceral fat), poor diet high in processed foods and sugar, sedentary lifestyle, chronic infections, autoimmune diseases, smoking, sleep apnea, and metabolic syndrome. Temporary spikes can occur with acute illness, injury, or intense exercise.
When should you see a doctor?
See your doctor if your hs-CRP is above 3.0 mg/L, as this indicates elevated cardiovascular risk. Levels above 10 mg/L may suggest an acute infection or inflammatory condition. If persistently elevated (2+ tests over several weeks), discuss comprehensive cardiovascular risk assessment including lipid panel and ApoB.
hs-CRP and longevity
Inflammaging — chronic, low-grade systemic inflammation — is recognized as a central hallmark of the biological aging process. When hs-CRP is persistently elevated, the arterial endothelium becomes inflamed and permeable, creating conditions where ApoB-containing particles can penetrate the intima layer, become oxidized, and trigger the cascade of atherosclerotic plaque formation. Beyond cardiovascular disease, chronic inflammation is linked to accelerated cognitive decline, increased cancer incidence, and impaired immune surveillance. The dietary ratio of omega-6 to omega-3 fatty acids is a key modifiable factor — the typical Western diet ratio of 15:1 is highly pro-inflammatory compared to the ideal 2-4:1. Specialized pro-resolving mediators (SPMs) derived from omega-3s actively resolve inflammation rather than merely suppressing it.
Where to get a hs-CRP test
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Related biomarkers
These biomarkers are often tested alongside hs-CRP for a more complete picture.
Frequently asked questions
What is a normal CRP level?
What is inflammaging?
What causes elevated CRP?
How can I lower my CRP?
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Sources: Reference ranges based on AHA/ACC, ADA, and AACE clinical guidelines. Biological variation data from Ricos/Westgard database. Longevity-optimal ranges reflect targets used by preventive and functional medicine practitioners.
Last reviewed: April 2026. This tool provides general health information and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider about your specific results.