The sedimentation rate (sed
rate) blood test measures how quickly red blood cells (erythrocytes) settle in
a test tube in one hour. The more red cells that fall to the bottom of the test
tube in one hour, the higher the sed rate.
inflammation is present in the body, certain
proteins cause red blood cells to stick together and
fall more quickly than normal to the bottom of the tube. These proteins are
produced by the liver and the
immune system under many abnormal conditions, such as
an infection, an
autoimmune disease, or cancer.
many possible causes of a high sedimentation rate. For this reason, a sed rate
is done with other tests to confirm a diagnosis. After a diagnosis has been
made, a sed rate can be done to help check on the disease or see how well
treatment is working.
A sedimentation rate (sed rate) test is
You do not need to do anything before
you have this test.
Talk to your doctor about any concerns you
have regarding the need for the test, its risks, how it will be done, or what
the results will mean. To help you understand the importance of this test, fill
medical test information form(What is a PDF document?).
The health professional drawing blood
The blood sample is taken from a vein in
your arm. An elastic band is wrapped around your upper arm. It may feel tight.
You may feel nothing at all from the needle, or you may feel a quick sting or
There is very little chance of a
problem from having a blood sample taken from a vein.
The sedimentation rate (sed rate) blood
test measures how quickly red blood cells (erythrocytes) settle in a test
The normal values listed here-called a reference range-are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Results are usually available right away.
millimeters per hour (mm/hr), or 0-20 mm/hr for men older than 50
0-20 mm/hr, or 0-30 mm/hr for women older than 50
High sedimentation rates may be caused
Low values may be caused by:
Reasons you may not be able to
have the test or why the results may not be helpful include:
CitationsFischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.Other Works ConsultedFischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.Pagana KD, Pagana TJ (2010). Mosby's Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
ByHealthwise StaffPrimary Medical ReviewerAnne C. Poinier, MD - Internal MedicineMartin J. Gabica, MD - Family MedicineE. Gregory Thompson, MD - Internal MedicineSpecialist Medical ReviewerAdam Husney, MD - Family Medicine
Current as ofDecember 8, 2016
Current as of:
December 8, 2016
Anne C. Poinier, MD - Internal Medicine & Martin J. Gabica, MD - Family Medicine & E. Gregory Thompson, MD - Internal Medicine & Adam Husney, MD - Family Medicine
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Last modified on: 8 September 2017