• Definition
    • ESR stands for erythrocyte sedimentation rate. It is commonly called a "sed rate."

      It is a test that indirectly measures how much inflammation is in the body.

  • Alternative Names
    • Erythrocyte sedimentation rate; Sed rate; Sedimentation rate

  • 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 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
  • 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
  • References
    • Pisetsky DS. Laboratory testing in the rheumatic diseases. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 257.