Describe ESR.

ESR, or erythrocyte sedimentation rate, is a blood test that measures how quickly red blood cells settle at the bottom of a test tube. It is a non-specific test that can indicate the presence of inflammation in the body. A high ESR level may be a sign of infection, autoimmune diseases, or other inflammatory conditions. The test is often used as a screening tool to help diagnose and monitor various medical conditions.

Erythrocyte Sedimentation Rate (ESR)

ESR is a blood test that measures the rate at which red blood cells (erythrocytes) settle at the bottom of a tube. It is a non-specific test used to assess inflammation or infection in the body.

Procedure:

- A blood sample is taken and placed in a thin, upright glass tube.
- The tube is allowed to stand undisturbed for one hour.
- After one hour, the distance the red blood cells have settled is measured in millimeters per hour (mm/hr).

Interpretation:

Normal Range:

- Men: 0-15 mm/hr
- Women: 0-20 mm/hr

Elevated ESR:

- An elevated ESR indicates an increased rate of inflammation or infection in the body.
- The higher the ESR, the greater the severity of the underlying condition.

Causes of Elevated ESR:

- Infections: Bacterial, viral, or parasitic infections
- Autoimmune diseases: Rheumatoid arthritis, lupus, Crohn's disease
- Chronic inflammation: Arthritis, asthma, chronic bronchitis
- Cancer: Leukemia, lymphoma, multiple myeloma
- Kidney disease
- Pregnancy

Factors Affecting ESR:

- Age: ESR increases with age.
- Sex: Women typically have a higher ESR than men.
- Hormones: Estrogen can increase ESR.
- Medications: Some medications, such as corticosteroids, can lower ESR.
- Physical activity: Recent exercise can temporarily elevate ESR.

Limitations:

- ESR is a non-specific test, meaning it cannot diagnose a specific condition.
- It can be affected by factors other than inflammation, such as blood viscosity and hematocrit.
- A normal ESR does not rule out the possibility of an inflammatory condition.