Apart from physiological differences in the way different areas of the body respond to meals, insulin, or physical activity, we are not aware of any health conditions or medications that would affect forearm results differently than finger results.

Certain conditions such as abnormal hematocrit levels or circulation problems can affect blood glucose results, regardless of the testing site location. Obtain finger results in conjunction with arm results to help assess whether the site to site difference is significant for that individual.

Under certain conditions, blood glucose test results obtained using samples from the forearm may differ significantly from fingertip samples. The conditions in which these differences are most likely to occur are when blood glucose is changing rapidly, such as during the two-hour period following a meal, insulin dose, or physical exercise. When blood glucose is falling, testing with a fingertip sample may identify a hypoglycemic (low blood sugar) level sooner than a test with an forearm sample. When initiating post-meal alternate site testing, obtain finger results in conjunction with forearm results to help assess whether the site to site differences are significant.