Erythrocyte Sedimentation Rate
The Erythrocyte Sedimentation Rate (ESR), also known as the sedimentation rate or sed rate, is a blood test that measures the rate at which red blood cells settle to the bottom of a tube of blood over a certain period of time. This test is used to evaluate various aspects of health:
- Inflammation: The ESR is a non-specific marker of inflammation. When inflammation is present in the body, certain proteins, including fibrinogen and immunoglobulins, cause red blood cells to clump together and settle more rapidly. An elevated ESR can indicate the presence of inflammation, but it doesn't provide information about the specific cause or location of the inflammation.
- Infection: Infections, whether bacterial, viral, fungal, or parasitic, can cause an increase in the ESR due to the body's inflammatory response. However, an elevated ESR alone is not diagnostic of infection and must be interpreted in conjunction with other clinical findings and tests.
- Autoimmune Diseases: Autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and giant cell arteritis, are characterized by chronic inflammation and can be associated with elevated ESR levels.
- Cancer: Some cancers, particularly those associated with inflammation or tissue damage, can cause an increase in the ESR. However, the ESR is not specific to cancer and may be elevated in various other conditions.
- Chronic Diseases: Chronic diseases such as chronic kidney disease, chronic obstructive pulmonary disease (COPD), and inflammatory bowel disease (IBD) can lead to persistent low-grade inflammation, resulting in an elevated ESR.
- Monitoring Response to Treatment: The ESR may be used to monitor response to treatment for inflammatory conditions. A decrease in the ESR over time may indicate improvement in the underlying inflammatory process.