ESR Test Results High vs. Low

Written by WebMD Editorial Contributors

• Why You Might Get a Sed Rate
• Taking the Blood Sample
• The Results and What They Mean
• Other Tests You May Need

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.

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.

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)

You might also get this test once you’ve started treatment for one of these conditions. The sed rate can help your doctor see how well your body is responding to treatment.

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.

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. 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

A high sed rate is a sign you have a disease that causes inflammation in your body.

Some conditions and medicines can affect the speed at which red blood cells fall, and they may affect your test results. These include:

• Anemia
• Older age
• Kidney problems
• Thyroid disease
• Pregnancy or having your period
• Obesity
• Drugs like birth control pills, methyldopa (Aldomet), theophylline (Theo-24, Theolair, Elixophylline), vitamin A, cortisone, and quinine

The sed rate test can only tell your doctor that you have inflammation somewhere in your body. It can’t show where the inflammation is or what caused it. Your doctor may also test for your erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) to help make a diagnosis. Both are acute phase reactants or inflammatory markers which can help point to a diagnosis or help follow treatment in a diagnosis. You will still need imaging or even biopsyies to make a specific diagnosis.

Talk to your doctor about the results of your sed rate test, and any other tests you have. Make sure you understand what the results mean, and how they’ll affect your treatment.

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ESR Information | Mount Sinai

Erythrocyte sedimentation rate; Sed rate; Sedimentation rate

ESR stands for erythrocyte sedimentation rate. It is commonly called a “sed rate.”

It is a test that indirectly measures the level of certain proteins in the blood. This measurement correlates with the amount of inflammation in the body.

Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.

How the Test is Performed

A blood sample is needed. Most of the time, blood is drawn from a vein located on the inside of the elbow or the back of the hand. 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 steps needed to prepare for this test.

How the Test will Feel

You may feel slight pain or a sting when the needle is inserted. You may also feel some throbbing at the site after the blood is drawn.

Why the Test is Performed

Reasons why a “sed rate” may be done include:

• Unexplained fevers
• Certain types of joint pain or arthritis
• Muscle symptoms
• Headache
• Other vague symptoms that cannot be explained

This test may also be used to monitor whether an illness is responding to treatment.

This test can be used to monitor inflammatory diseases or cancer. It is not used to diagnose a specific disorder.

However, the test is useful for detecting and monitoring:

• Autoimmune disorders
• Bone infections
• Certain forms of arthritis
• Inflammatory diseases

Normal Results

For 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

For children (Westergren method):

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

Note: mm/hr = millimeters per hour

Normal value ranges may vary slightly among different laboratories. Talk to your health care provider about the meaning of your specific test results.

What Abnormal Results Mean

An abnormal ESR may help with a diagnosis, but it does not prove that you have a certain condition. Other tests are almost always needed.

An increased ESR rate may occur in people with:

• Anemia
• Cancers such as lymphoma or multiple myeloma
• Kidney disease
• Pregnancy
• Thyroid disease

The immune system helps protect the body against harmful substances. An autoimmune disorder is when the immune system mistakenly attacks and destroys healthy body tissue. ESR is often higher than normal in people with an autoimmune disorder.

Common autoimmune disorders include:

• Lupus
• Polymyalgia rheumatica
• Rheumatoid arthritis in adults or children

Very high ESR levels occur with less common autoimmune or other disorders, including:

• Allergic vasculitis
• Giant cell arteritis
• Hyperfibrinogenemia (increased fibrinogen levels in the blood)  
• Macroglobulinemia – primary
• Necrotizing vasculitis

An increased ESR rate may be due to some infections, including:

• Bodywide (systemic) infection
• Bone infections
• Infection of the heart or heart valves
• Rheumatic fever
• Severe skin infections, such as erysipelas
• Tuberculosis

Lower-than-normal levels occur with:

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

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