Erythrocyte Sedimentation Rate

The sedimentation rate or `sed rate`, for short is a blood test that checks for inflammation in your body. It’s one clue for your doctor that you might have a disease linked to inflammation, like arthritis or cancer, or an infection.

What is ESR? #

• The sed rate test measures how fast red blood cells fall to the bottom of a tube.

• Inflammation creates proteins that make red blood cells fall more quickly.

• Another name for this test is erythrocyte sedimentation rate (ESR).

• Red blood cells are called erythrocytes.

• Sedimentation is the process by which they fall to the bottom of the tube.

Why you might get ESR #

Your doctor might order the sed rate test if you have symptoms like these:

• Headaches

• Stiff, swollen, or painful joints

• Pain in your shoulders, neck, or pelvis

• Appetite loss

• Weight loss without trying

The sed rate test can be part of the process of discovering if you have one of these conditions:

• Infection (including of the bones)

• Cancer

• Arteritis (inflammation of the blood vessels)

• Lupus (an autoimmune disease that damages the skin, joints, and other parts of your body)

• Polymyalgia rheumatica (causes stiff and painful muscles)

• Rheumatoid arthritis (autoimmune disease in which the immune system attacks your joints)

• Systematic vasculitis (inflammation in your blood vessels)

Procedure of ESR #

• You don’t need to do anything special to prepare.

• It’s just a basic blood test.

• Let your doctor know what medicines (and supplements) you take before you have the test.

• Certain drugs can affect the results.

• Also let your doctor know if you are pregnant or are having your period.

• A nurse or other health care provider will take a sample of your blood, usually from a vein in your arm.

• They will first tie a band around the upper part of your arm to make your vein fill with blood and swell up.

• Then they’ll clean the area with an antiseptic, and place a needle into your vein.

• Your blood will collect into a vial or tube.

• The process should only take a couple of minutes.

• Afterward, you’ll get a piece of gauze and a bandage over the area to stop the bleeding.

• You may feel a slight sting as your blood is drawn.

• Afterward, you may have a small bruise.

• You might feel dizzy and sore, and there might be some bleeding.

Normal ranges of ESR #

The normal range is:

• 0 to 15 mm/hour in men younger than 50

• 0 to 20 mm/hour in men older than 50

• 0 to 20 mm/hour in women younger than 50

• 0 to 30 mm/hour for women older than 50

What does ESR test result means #

• Your sample will go to a lab. You should have the results in 1 or 2 hours.

• A lab technician will place your red blood cells into a tall, thin tube and check how far they fall in 1 hour.

• When you have inflammation in your body, abnormal proteins in your blood make red blood cells form into clumps.

• These clumps are heavy, so they fall to the bottom of the tube more quickly than single blood cells.

• The faster the blood cells sink, the more inflammation you have in your body.

• The sed rate test reports in millimeters (mm) the distance between the clear liquid (plasma) at the top of the tube and your red blood cells after 1 hour.