From the Guidelines
The ESR level is typically considered elevated when it exceeds 20-30 mm/hr, depending on age and gender, and is often used as a non-specific indicator of inflammation in the body. The ESR test measures how quickly red blood cells settle to the bottom of a test tube, with inflammation causing proteins in blood to clump red blood cells together, making them heavier and causing them to settle faster 1. In the context of giant cell arteritis, an ESR level above 50 mm/hr has been found to have a sensitivity of 78.9% and a specificity of 43.5% for diagnosis, while an ESR level above 60 mm/hr has a sensitivity of 70.7% and a specificity of 70.5% 1. It's essential to interpret ESR levels in conjunction with other clinical findings and tests, as it can be affected by various factors such as pregnancy, anemia, and certain medications. For instance, in the diagnosis of Kawasaki disease, the ESR is often above 40 mm per hour and can be elevated to levels of at least 100 mm per hour, while the C-reactive protein (CRP) level typically reaches levels of 3 mg per dL (30.0 mg per L) or more 1. Key points to consider when evaluating ESR levels include:
- Normal ESR levels vary by age and gender
- Elevated ESR levels indicate inflammation but do not identify its specific cause
- ESR should be interpreted alongside other tests and clinical findings
- Factors like pregnancy, anemia, and certain medications can affect ESR levels.
From the Research
Erythrocyte Sedimentation Rate (ESR) Level
The ESR level is a measure of inflammatory conditions, and its value can be influenced by various factors.
- The normal ESR value can vary depending on age, sex, and other physiological factors 2, 3.
- Studies have shown that ESR levels increase with age, with median ESR values being higher in females than in males, and increasing steadily with age 3.
- The ESR level can also be affected by lifestyle factors such as physical activity, smoking, and alcohol consumption, as well as common metabolic abnormalities like obesity and metabolic syndrome 3.
- In patients with chronic hemodialysis, the hematocrit-corrected ESR level can be useful in diagnosing inflammation, with a value of 23 mm/h indicating normal conditions and 59 mm/h indicating severe inflammation 2.
- However, ESR levels can be influenced by various factors, including noninfectious conditions, resolution of inflammation, and underlying diseases like renal insufficiency and low albumin, which can lead to discordance between ESR and C-reactive protein (CRP) measurements 4, 5.
Factors Influencing ESR Levels
Several factors can influence ESR levels, including:
- Demographic factors like age and sex 3
- Lifestyle factors like physical activity, smoking, and alcohol consumption 3
- Metabolic abnormalities like obesity and metabolic syndrome 3
- Underlying diseases like renal insufficiency and low albumin 4, 2
- Noninfectious conditions and resolution of inflammation 5
Clinical Significance of ESR Levels
ESR levels can be useful in diagnosing and monitoring inflammatory conditions, but should be used in combination with clinical history and physical examination 6, 5.