ESR Health Article

Definition

ESR stands for erythrocyte sedimentation rate. It is a test that indirectly measures how much inflammation is in the body. However, it rarely leads directly to a specific diagnosis.

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 site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

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, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

The blood sample is sent to a lab. The test measures how fast red blood cells called erythrocytes fall to the bottom of a tall, thin tube.

How to prepare for the test

There are no special preparations needed.

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

This test can be used to monitor inflammatory or cancerous diseases. It is a screening test, which means it cannot be used to diagnose a specific disorder.

However, it is useful in detecting and monitoring tuberculosis, tissue death, certain forms of arthritis, autoimmune disorders, and inflammatory diseases that cause vague symptoms.