What Is ESR in a Blood Test?

ESR stands for Erythrocyte Sedimentation Rate (sed rate). Measures how quickly red blood cells settle in a tube in one hour. Inflammation causes faster settling.

Normal Ranges

• Men under 50: below 15 mm/hr
• Men over 50: below 20 mm/hr
• Women under 50: below 20 mm/hr
• Women over 50: below 30 mm/hr
• Increases with age: age/2 for men, (age+10)/2 for women

Elevated ESR Causes

• Infection — bacterial, TB, osteomyelitis
• Autoimmune disease — RA, lupus, polymyalgia rheumatica, temporal arteritis
• Kidney disease
• Pregnancy
• Anemia
• Cancer — lymphoma, multiple myeloma
• Thyroid disease

ESR vs CRP

• CRP rises within hours; ESR takes days
• CRP normalizes quickly; ESR stays elevated for weeks
• ESR increases with age; CRP is less age-dependent
• Both are non-specific — indicate inflammation but not its cause