Sedimentation Rate (Sed Rate)
How It Feels
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.
- You may get a small bruise at the puncture
site. You can reduce the risk of bruising by keeping pressure on the site for
several minutes after the needle is withdrawn.
- In rare cases, the
vein may become inflamed after the blood sample is taken. This condition is
called phlebitis and is usually treated with a warm compress applied several
- Continued bleeding can be a problem for people with
bleeding disorders. Aspirin, warfarin (Coumadin), and other blood-thinning
medicines can also make bleeding more likely. If you have bleeding or clotting
problems, or if you take blood-thinning medicine, tell your health professional
before your blood is drawn.
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: