How to read inflammatory markers (CRP and ESR)
Other platforms explain it with text and video. In VMS you practice it on the patient.
CRP and ESR show that inflammation is present but not where or why. They are most useful for tracking a known condition over time.
Step by step
Know what they measure
CRP is a protein made by the liver during inflammation. ESR measures how fast red cells settle in a tube. [1]
Know the speed
CRP rises within hours and falls quickly when inflammation settles. ESR rises and falls over days to weeks. [1]
Check the units
CRP may be reported in mg/L or mg/dL. A value of 10 mg/L is the same as 1 mg/dL. [2]
Adjust ESR for the patient
ESR rises with age and is higher in women, in anemia, in pregnancy and in kidney disease. [1]
Read very high values
An ESR over 100 mm/hr suggests serious infection such as bone infection, cancer such as myeloma, or vasculitis such as giant cell arteritis. [1]
Use them in context
They help in suspected giant cell arteritis, polymyalgia rheumatica and to track bone and joint infections. A normal result does not rule out disease. [1]
Common errors
- Using a raised CRP alone to diagnose infection.
- Mixing up mg/L and mg/dL.
- Using the same ESR limit for every age.
Typical adult values; use your lab's ranges [1]
| Test | Typical normal | Notes |
|---|---|---|
| CRP | Under about 10 mg/L (1 mg/dL) | Rises in hours, falls fast |
| High-sensitivity CRP | Under 1 mg/L low risk; over 3 mg/L higher risk | Used for heart risk, not acute illness |
| ESR (men) | Up to about age divided by 2 mm/hr | Rises with age |
| ESR (women) | Up to about (age plus 10) divided by 2 mm/hr | Higher in women and in anemia |
Practice it in VMS
In VMS you do this on the patient, not on paper: every step goes on the checklist with a score, and in Teach mode Blocky tells you what comes next.
VMS cases that train this skill
Sources
Facts and steps follow AAMC Core Entrustable Professional Activities (Core EPAs); NCCPA PANCE Content Blueprint. VMS is not affiliated with these organizations. Updated: 2026-10-11.