Inflammation Markers — ESR, CRP & the Fire Inside
AHA Scientific Statement on Inflammatory Biomarkers & European Heart Journal Inflammation Guidelines
Educational content only. This information is for general awareness and does not constitute medical advice. Please consult a qualified healthcare provider for any medical concerns or before making health decisions.
Key Facts
60%+
Chronic diseases linked to inflammation
Heart disease, diabetes, cancer, Alzheimer's share an inflammatory basis
3×
High hs-CRP cardiac risk increase
Individuals with hs-CRP > 3 mg/L face triple the cardiac event risk
< 20 mm/hr
Normal ESR (adult women)
ESR rises with age — always interpret with age-adjusted norms
6–8 hours
CRP response time
CRP rises rapidly after tissue injury or infection — faster than ESR
What Is Inflammation and Why Does It Matter?
Inflammation is the immune system's response to injury or infection. Acute inflammation — the redness, swelling, and heat after a cut — is protective and resolves within days.
Chronic low-grade inflammation: is different: it is silent, persists for months to years, and damages tissues. It underpins the pathology of:
• Cardiovascular disease (inflamed arterial walls accumulate plaque)
• Type 2 diabetes (inflammatory cytokines cause insulin resistance)
• Cancer (chronic inflammation promotes tumour microenvironments)
• Autoimmune diseases (misdirected inflammation attacks self-tissue)
• Alzheimer's disease (neuroinflammation degrades neurons)
Inflammation markers in blood provide a systemic signal that this process is active — often long before organ damage becomes visible.
ESR (Erythrocyte Sedimentation Rate)
ESR measures how quickly red blood cells settle to the bottom of a test tube. Inflammation causes certain proteins to coat red cells, making them clump and sink faster.
Normal values::
• Men: < 15 mm/hr
• Women: < 20 mm/hr (rises further with age)
Elevated ESR suggests::
• Infection (bacterial, viral, TB)
• Autoimmune conditions (rheumatoid arthritis, lupus, vasculitis)
• Anaemia
• Kidney disease
• Cancer (especially multiple myeloma and lymphoma)
• Inflammatory bowel disease
ESR is non-specific — it tells you inflammation is present but not where it is. It is a screening tool used alongside other markers and clinical examination.
ESR is particularly useful for monitoring:: In known inflammatory or autoimmune disease, serial ESR measurements track disease activity and treatment response.
CRP and hs-CRP — The More Precise Detectors
CRP (C-Reactive Protein): is synthesised by the liver within 6–8 hours of tissue injury or inflammation. It rises steeply (up to 1000-fold) in acute infection or trauma and falls quickly when the trigger resolves — making it more dynamic and specific than ESR.
Standard CRP:: Best for detecting significant infection or acute inflammation. Normal: < 5 mg/L. Values > 10 mg/L suggest significant infection or inflammatory disease.
hs-CRP (High-Sensitivity CRP):: Same protein, but measured with a far more sensitive assay capable of detecting the low-level chronic inflammation associated with cardiovascular risk.
hs-CRP cardiovascular risk stratification::
• < 1 mg/L: Low cardiovascular risk
• 1–3 mg/L: Intermediate risk
• > 3 mg/L: High risk — consider statin therapy regardless of cholesterol levels (per ACC/AHA guidelines)
hs-CRP is one of the best predictors of future heart attack risk — better than LDL cholesterol alone in many studies. The JUPITER trial showed statin therapy in people with high hs-CRP but normal LDL dramatically reduced cardiac events.
Other Inflammation Markers
Serum Ferritin:: An acute-phase reactant — rises sharply in inflammation and infection. In the context of anaemia workup, very high ferritin despite anaemia points to 'anaemia of chronic disease' rather than iron deficiency.
Fibrinogen:: Clotting protein elevated in inflammation — an independent cardiovascular risk factor. Also elevated in pregnancy and smoking.
IL-6 (Interleukin-6):: A key pro-inflammatory cytokine. Elevated in sepsis, autoimmune disease, and cancer. Increasingly used in critical care monitoring.
Procalcitonin (PCT):: Rises dramatically in bacterial infections but not viral ones — useful for deciding whether antibiotics are warranted. Normal: < 0.5 ng/mL.
Who Should Get Inflammation Marker Tests?
• Anyone with symptoms of infection that aren't resolving (persistent fever, fatigue, malaise)
• Individuals with known autoimmune conditions monitoring disease activity
• Patients with cardiovascular risk factors (add hs-CRP to lipid panel)
• Diabetics (chronic inflammation worsens insulin resistance)
• Those with unexplained fatigue, joint pain, or recurrent illness
• Annual hs-CRP recommended for anyone over 45 with cardiovascular risk factors
Related Insights
Heart Health Tests — Beyond Basic Cholesterol
Cardiac risk is about much more than LDL. Modern risk panels include hs-CRP, homocysteine, and Lp(a) — markers that reveal hidden inflammation and genetic risk.
Autoimmune Disorders — ANA, Rheumatoid Factor & the Immune System Turned Inward
When the immune system attacks the body's own tissues, the resulting diseases are diverse, often misdiagnosed, and detectable years before serious damage through specific blood markers.