ESR

The erythrocyte sedimentation rate (ESR), also known as the sed rate, is a common hematology test that measures how quickly erythrocytes (red blood cells) settle at the bottom of a test tube over a specified period. The test is a non-specific measure of inflammation and is often used to help diagnose conditions associated with acute and chronic inflammation, including infections, cancers, and autoimmune diseases.

Procedure

The ESR test involves drawing a small amount of blood from the patient, which is then placed in a tall, thin tube. The rate at which the red blood cells fall to the bottom of the tube is measured in millimeters per hour (mm/hr). A higher rate indicates the presence of inflammation.

Clinical Significance

An elevated ESR can indicate the presence of an inflammatory condition, such as rheumatoid arthritis, systemic lupus erythematosus, or temporal arteritis. It can also be elevated in cases of infection, such as tuberculosis or pneumonia, and in certain cancers, such as lymphoma or multiple myeloma. However, because the ESR is a non-specific test, it must be used in conjunction with other diagnostic tests and clinical evaluations.

Factors Affecting ESR

Several factors can influence the ESR, including age, sex, and certain medical conditions. For example, ESR tends to be higher in older adults and women. Conditions such as anemia, kidney disease, and pregnancy can also affect the ESR.

Normal Values

Normal ESR values can vary depending on the laboratory and the method used. Generally, normal values are:

• Men: 0-15 mm/hr
• Women: 0-20 mm/hr
• Children: 0-10 mm/hr

Related Tests

Other tests that may be used in conjunction with the ESR to diagnose inflammatory conditions include the C-reactive protein (CRP) test, the complete blood count (CBC), and various autoantibody tests.

See Also

• C-reactive protein
• Complete blood count
• Rheumatoid arthritis
• Systemic lupus erythematosus
• Temporal arteritis
• Inflammation