ESR

Definition

ESR (erythrocyte sedimentation rate) is a nonspecific screening test for various diseases. This 1-hour test measures the distance (in millimeters) that red blood cells settle in unclotted blood toward the bottom of a specially marked test tube.

Alternative Names

Erythrocyte sedimentation rate; Sed rate; Sedimentation rate

How the test is performed

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and a band or blood pressure cuff is placed around the upper arm to apply pressure and cause the veins below the band to fill with blood.

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children:

The area is cleaned with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. A bandage may be applied to the puncture site if there is any continued bleeding.

How to prepare for the test

There are no food or fluid restrictions.

How the test will feel

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the test is performed

The erythrocyte sedimentation rate (ESR) can be used to monitor inflammatory or malignant disease. Although it is a screening test (cannot be used to diagnose a specific disorder), it is useful in detecting and monitoring tuberculosis, tissue necrosis (death), rheumatologic disorders, or an otherwise unsuspected disease in which symptoms are vague or physical findings are minimal.

Normal Values

Adults (Westergren method):

• Men under 50 years old: less than 15 mm/hr.
• Men over 50 years old: less than 20 mm/hr.
• Women under 50 years old: less than 20 mm/hr.
• Women over 50 years old: less than 30 mm/hr.

Children (Westergren method):

• Newborn: 0 to 2 mm/hr.
• Neonatal to puberty: 3 to 13 mm/hr.

Note: mm/hr. = millimeters per hour.

What abnormal results mean

Elevated values occur with:

• Kidney disease
• Pregnancy
• Rheumatic fever
• Rheumatoid arthritis
• Severeanemia
• Syphilis
• Systemic lupus erythematosus
• Thyroid disease
• Tuberculosis
• Other inflammatory conditions

Markedly elevated values occur with:

• Giant cell arteritis
• Multiple myeloma
• Macroglobulinemia - primary
• Hyperfibrinogenemia (elevated fibrinogen levels in the blood)
• Necrotizing vasculitis
• Polymyalgia rheumatica

Lower-than-normal levels occur with:

• Congestive heart failure
• Hyperviscosity
• Hypofibrinogenemia (decreased fibrinogen levels)
• Low plasma protein (due to liver or kidney disease)
• Polycythemia
• Sickle cell anemia

Additional conditions that may affect test results:

• Allergic vasculitis
• Atrial myxoma
• Autoimmune hepatitis
• Endometritis
• Eosinophilic fasciitis
• Erysipelas
• Juvenile rheumatoid arthritis
• Legionnaire's disease
• Osteomyelitis
• Pelvic inflammatory disease (PID)
• Pericarditis, post-MI
• Retroperitoneal fibrosis
• Skin lesion of blastomycosis
• Subacute thyroiditis
• Systemic sclerosis (scleroderma)

What the risks are

• Excessive bleeding
• Fainting or feeling lightheaded
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)
• Multiple punctures to locate veins

Special considerations

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

•	Pulmonary tuberculosis
•	Necrosis
•	Kidney disease
•	Rheumatoid arthritis
•	Anemia
•	Syphilis
•	Systemic lupus erythematosu...
•	Thyroid diseases
•	Temporal arteritis
•	Multiple myeloma