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Diabetes 101 Alternate Site Testing Nutrition Tips Exercise and Diabetes Diabetes and Your Health Diabetes Facts Diabetes Tips Diabetes Glossary

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How do I perform an alternate site test?

The following graphic shows the general steps involved in forearm testing. First, you vigorously rub the area until it's warm to increase blood flow to the surface. Second, you lance the arm. Third, you touch the test strip to the blood drop. It's that easy. For more information on how to perform a blood glucose test, please refer to your user's guide for your meter.

Important information about forearm testing

You can choose fingertip, forearm, palm, thigh, calf or foot testing with multi-site Blood Glucose Monitoring Systems. Forearm testing may mean less pain because your arm has fewer nerve endings than your fingertips. Before you try testing on your forearm, read your owner's manual to understand when and how to forearm test and talk to your health care professional.

When to forearm test

Although forearm testing can give sensitive fingertips a break from testing, forearm testing should only be used at the right times. Studies show that test results using samples taken from the forearm may differ from fingertip samples when blood glucose is changing rapidly, such as within two hours after a meal, an insulin dose or exercise.

• Only use forearm testing before a meal, an insulin dose or physical exercise, or two hours after a meal, an insulin dose or exercise.
• If you test within two hours after a meal, an insulin dose or exercise, you should test from your finger.
• When blood glucose is changing rapidly, fingertip samples show these changes more quickly than forearm samples.
• When your blood glucose is falling, testing with a fingertip may identify a hypoglycemic (low blood sugar) level sooner than a test with a forearm sample.
• You should use fingertip testing whenever you have a concern about hypoglycemia (insulin reactions), such as when you drive a car, particularly if you suffer from hypoglycemic unawareness (lack of symptoms to indicate an insulin reaction), since forearm testing may fail to detect hypoglycemia.
• If the results from the forearm do not match how you feel (high or low), test from the fingertip and use those results.

Some tips to help you successfully test on your forearm:

• Before you test, rub your forearm.
• Choose an area that's free of hair and obvious veins.
• When using the lancet device, use the clear cap. This lets you view the test site so you can see when you have an adequate blood sample from the forearm.
• Hold the lancing device on the forearm for 5 seconds to allow an adequate blood sample to collect on the surface. The clear cap allows you to see your sample.

Related Topics

• Why is alternate site testing less painful?
• Using AST Meter - Where can I test?
• When is testing on the finger preferred?
• Testing on the finger is recommended if...
• How would I know if I have hypoglycemia unawareness?
• Why are there differences between forearm and fingertip results?
• What is the percentage of difference when comparing results from the forearm to a result from a fingerstick test result?
• Which result should be used to determine how much medication to take if there is a difference between a forearm test and a fingerstick test?
• Can sample size affect the result?