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 risk of a problem from
having blood drawn from a vein.
- You may develop 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after the needle is withdrawn.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 times
- 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.
A blood glucose test measures the amount of
a type of sugar, called glucose, in your blood.
Results are often
ready in 1 to 2 hours. Glucose levels in a blood sample taken from your vein
(called a blood plasma value) may differ a little from glucose levels checked
with a finger stick.
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.
Less than or equal to 100 milligrams per deciliter (mg/dL) (5.6 millimoles per liter, or mmol/L).
2 hours after eating (postprandial):2
Less than 140 mg/dL
(7.8 mmol/L) for people age 50 and younger; less than 150 mg/dL (8.3 mmol/L) for people ages 50–60; less than 160 mg/dL (8.9 mmol/L) for people age 60 and older.
Levels vary depending on when and how much you ate at your last meal. In general: 80–120 mg/dL
(4.4–6.6 mmol/L) before meals or when waking up; 100–140 mg/dL (5.5–7.7 mmol/L) at bedtime.