RESULTS
■Never use your meter with blood that has been placed in a gray top test tube.
A variation between meter and lab results can occur because blood glu- cose levels can change significantly over short periods, especially if you have recently eaten, exercised, taken medication, or experienced stress.7 In addition, if you have eaten recently, the blood glucose level from a finger- stick can be up to 3.9 mmol/L higher than blood drawn from a vein (venous sample) used for a lab test.8 It is there- fore best to fast for eight hours before doing comparison tests. Factors such as the amount of red blood cells in
the blood (a high or low hematocrit) or the loss of body fluid (severe dehy- dration) may also give a meter result different from a laboratory result. For more detail, see Health Conditions Causing
Expected Test Results (Target Range)
Your test results will vary somewhat from test to test because blood glucose levels change throughout the day. The types and amounts of food you eat, your activity and stress levels, and the insulin or other medication you take affect your blood glucose levels. If you are controlling your diabetes well,
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