Although blood glucose meters are simple to operate, many things can go wrong. Follow the tips below to get the most accurate results from your blood glucose meter. Preparing to Test Read and save all instructions for your meter and test strips. Watch and practice with an experienced blood glucose meter user, a diabetes educator, or a healthcare professional. Don't be afraid to ask questions! Wash your hands. Even small amounts of food or sugar on your fingers can affect your results. Do not use test strips from a cracked or damaged bottle. Do not use test strips that have passed their expiration dates. Make sure you have entered the correct calibration code (if your meter requires one). Even if an incorrect test strip fits in your meter, it could give you wrong results. Test strips may look alike, but they are not all the same. Strips often have very specific chemical coatings or sizes. Read the test strip packaging to make sure the strips will work with your meter. Testing Your Blood Glucose Use the correct blood drop size. If there is not enough blood on the test strip, the meter may not read the blood glucose level accurately. Repeat the test if you have any doubts. Let the blood flow freely from your fingertip; do not squeeze your finger. Squeezing your finger can affect the results. Use a whole test strip each time you use your meter. Insert the test strip into the meter until you feel it stop against the end of the meter guide. Even if your meter is supposed to give an error message when the blood drop is too small, the message may appear only when the drop is much too small. If the blood drop is too small, your meter can be wrong without giving an error message! Maintaining Your Blood Glucose Meter Keep your meter clean. Test your meter regularly with control solution. Keep extra batteries charged and ready. Store your meter and supplies properly. Heat and humidity can damage test strips. Replace the bottle cap promptly after removing a test strip. Note on Alternative Site Testing Some blood glucose meters can use blood samples from the upper arm, forearm, base of the thumb, or thigh. Using alternative sites gives you more options. But be aware that blood glucose levels from these sites may not always be as accurate as readings from the fingertips. Alternative site results differ from fingertip results when glucose levels are changing rapidly such as after a meal, after taking insulin, during exercise, or when you are ill or under stress.