As a diabetes educator, I have heard this statement from many hundreds of people. Self monitoring of blood glucose (blood sugar) is a cornerstone of modern diabetes care. And right now, we still don't have any way to check blood glucose without using a drop of blood. So it's certainly true, if you check your blood glucose regularly. it is possible to make your fingertips really sore. And, of course, if your fingers are already sore, you are not going to want to poke them again to get one more drop of blood for one more check of your blood glucose.