Understanding ESR and CRP: What Your Doctor's Results Mean

Erythrocyte Sedimentation Rate (ESR) and C-reactive Protein (CRP) are commonly ordered together to diagnose and monitor inflammatory conditions.

ESR

Measures how quickly red blood cells settle in a test tube. Inflammation increases blood proteins, causing cells to clump and settle faster (higher ESR). Non-specific—elevated in infections, inflammatory diseases (arthritis, lupus), cancer, pregnancy, anemia, kidney/liver/thyroid disease.

CRP

Liver-produced protein that rises quickly (within hours) in response to inflammation, peaking at 24–48 hours. More sensitive and specific than ESR for inflammation, but can also elevate in obesity, diabetes, heart disease, kidney/liver disease.

Interpretation

High ESR or CRP suggests inflammation; specific cause requires further testing. Used to:

• Diagnose inflammatory conditions
• Monitor disease progression
• Assess treatment response

Tracking levels over time helps doctors understand disease course and adjust treatment.