June 13, 2001
Blood Tests and Insulin Injections
Question from Brandenburg, Kentucky, USA:
I am 34 year old female with type�2 diabetes for the past three years, and when I check my sugar levels on my meter, I will get different readings from different fingers. I can poke one finger and have a reading of 82 mg/dl [4.6 mmol/L], then poke the finger next to it and it will read 92 mg/dl [5.1 mmol/L], so then I will recheck the first finger and it will now read 102 mg/dl [ 5.7 mmol/L]. I wash my hands thoroughly each time and use an alcohol swab each time. I ran the test on the meter to check it for accuracy, and everything shows to be in working order. Is there something I'm doing wrong? Is there a reason for this?
You have asked a good question. It is common for this difference in blood sugar to be experienced by people. The meter you are using is not a $100,000.00 machine like in a laboratory. It is small and often given away. It is possible that you can experience a 10% difference test to test, just as you have found out.
This is not usually a problem for people as it is a small difference and wouldn’t necessary change a medicine or insulin dose, but it can cause some frustration. A blood sugar of 195 mg/dl [10.8 mmol/L] would sound a lot better than 203 mg/dl [11.3 mmol/L]. In actuality, they are the same.
You have done all the troubleshooting around any skin differences, but you might want to double check your meter every now and again by using control solution to check machine accuracy. If you do not have any, you can contact the manufacturer directly by calling the 1-800 number on the back of your meter. They are usually willing to send you some free of charge.