ESR

Erythrocyte sedimentation rate; Sed rate; Sedimentation rate

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.

There are no special steps needed to prepare for this test.

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.

Reasons why a "sed rate" may be done include:

• Unexplained fevers
• Certain types of arthritis
• Muscle symptoms
• 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 that cause vague symptoms
• Tissue death

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.

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 be due to:

• 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
• Rheumatoid arthritis in adults or children

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

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

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

• Body-wide (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