Fingertip versus alternate site testing: benefits and drawbacks
For many years, those with diabetes faced the constant pain and irritation of fingertip sticks to get a blood sample. Those who worked with their hands, such as musicians or mechanics, faced even more challenges to regular glucose checking. Advances in meter technology made alternate site testing possible. "Meters used a lot more blood then than they do now," said Patty Bonsignore, RN-CDE at Joslin Diabetes Center. "Now that they use so little blood, it is possible to get an accurate reading from other sites."
Alternate site testing: what you test matters
But under some circumstances, the alternate site reading might not always be accurate. "Alternate site checking is good if you use it at the right time," Bonsignore said. "If the glucose is changing rapidly, you want to use fingertips. Changes in blood glucose show up more rapidly there than they do in the upper or lower arms, which is typically where alternate site checking is done."
Knowing the right way to test from alternate sites also makes a difference. "It does take a little bit of dexterity to use alternate site checking, so it helps to have a pharmacist or nurse show you how to do it the proper way," Bonsignore said.
There is one alternate site that can be just as easy as your fingertips. "Though the palm is considered an alternate site, it is actually just as accurate as the fingertips," Bonsignore said. "If you want to give your fingertips a break but don't want to take blood from your arm or thigh, go with the palm."
Six tips for fingertip and alternate site testing
Whether you are using fingertip testing or going with an alternate site, keep these pointers in mind for the most accurate results:
- Rub the alternate site vigorously before testing. That gets more circulation to the area, can give a more accurate reading and makes getting blood easier.
- Use fingertips if you have exercised or eaten within the two hours prior to your test.
- Always use fingertips for testing if you suspect your glucose is low.
- Those with hypoglycemia unawareness should always use fingertip testing.
- If you are pregnant, check your blood sugar with fingertips only.
- Since most people have stable blood sugars overnight, alternate site testing first thing in the morning is likely to be accurate.
Whether you get a drop of blood from your fingertip or your thigh, testing regularly is very important. Get in the habit of regular blood glucose checks, record the results and share the information with your doctor at each visit.
Interview with Patty Bonsignore, RN-CDE, Joslin Diabetes Center
BD, "Alternate Blood Glucose Testing"