An alternative blood testing site is a body location other than your fingertip where you can reliably test your blood glucose. Common alternative blood testing sites include the palm, forearm, upper arm, thigh, and calf.
Using alternative body sites for blood sugar testing has been a relief to many with type 1 diabetes who have suffered from chronically sore fingers from multiple tests each day. Of course, people with diabetes have been using alternative sites for years, but only recently do we have research available to show this is OK (meaning, these sites give accurate results). Also, the majority of (but not all) glucose meters are designed to support alternative testing.
Before you use an alternative site, discuss it with your doctor. Read the instructions for your blood glucose meter and only use sites that are identified in the instructions.
Blood Glucose Results May Vary With Alternate Sites
It is important to know that blood sugar results can vary depending on when and where you test your blood. For example, if you get a sample of blood from a testing site on your thigh and your blood sugar is going up significantly at the time, you may get a delayed result. In other words, the result you receive may be what your blood sugar was 20 to 30 minutes ago but it is not accurate for the present moment. You might be able to speed up the process slightly by rubbing the area until it is warm to increase blood flow to that site.
This doesn’t mean you shouldn’t use alternative test sites but they may not give an accurate result when glucose levels are apt to change rapidly, such as after a meal, after taking insulin, during exercise or when you are sick or experiencing stress. When you need an immediate, present-moment result, such as when you suspect low blood sugar, always use a finger test site.
When Not to Use Alternative Site Testing
There are circumstances when alternative testing is not recommended. These include:
- When you have just taken insulin
- During or after exercise
- If you feel you might be experiencing low blood sugar
- When you are preparing to drive
- When you are or suspect that you are ill
- Do not use an alternative site unless you have discussed it with your doctor first and you are able to follow his recommendations.,
- Do not use an alternative site unless it is identified in the instructions for your blood glucose meter.
Hypoglycemic Awareness Factors Into Using Alternate Sites
Some people with diabetes also have difficulty sensing the bodily signals of low blood sugar. Their hypoglycemic awareness has been blunted over time and they may not be able to accurately assess when blood sugar is going low. Though blood sugar testing is the only way to know for certain whether glucose levels are dropping, alternative site testing is not recommended for people who struggle with hypoglycemic awareness. Discuss it with your doctor before you do alternate site testing.