Alternate Blood Sugar Testing: What to Know


People with type 2 diabetes need to keep track of their blood sugar to reduce the risks of complications and achieve any other health-related goals. The information obtained from self-monitoring from blood glucose meters can be invaluable because it helps you and your provider make the best decisions about your diabetes care.

The conventional way to do it is by checking your blood sugar on a regular basis using a blood glucose meter (BGM) or a continuous glucose monitor (CGM). When diagnosed with diabetes, a healthcare provider gives instructions on how to test blood glucose using a lancing device, test strip and a meter. These checks are typically conducted at the fingertips. But did you know it’s possible to check your blood sugar in a place other than your fingers? This is called alternate site testing (AST). In this article, we explore:

● Why people with diabetes would check their blood sugar in places other than their fingertips.

● If glucose readings are more, less, or just as accurate as testing on your fingers.

● When it’s okay to use an alternative site to check blood sugar.

Where are Alternate Glucose Test Sites and Why Would a Person with Type 2 Diabetes Use Them?

Some with diabetes would prefer to use an alternative site to check their blood glucose because the traditional method is more painful. Other areas of the body such as your palm, legs, forearm, upper arm and stomach, are less sensitive areas compared to the fingertips, which have more nerve endings, and therefore make testing more painful.

One of the obstacles to managing diabetes is the fear of needles and the pain that comes with testing. It’s normal to want to avoid the pain and discomfort that comes with self-monitoring. But, fortunately, today’s lancing devices can adjust the puncture depths to ensure patients only prick their fingers are deep as necessary to get a good, accurate test result.

Is Alternate Site Testing as Accurate as Traditional Finger Pricks?

In short, yes. Alternative site testing can provide similar results as traditional finger pricks. However, this doesn’t mean they are a suitable replacement for the conventional method of checking blood sugar.

Why? Because alternative site testing may lag behind traditional finger-pricks by 20 minutes and glucose arrives faster in the fingertips than the other parts of your body. In addition to that, AST provides similar results when your blood glucose levels are steady and not falling or rising rapidly.

When to and When Not to Use Alternative Site Testing

If you’re considering checking your blood sugar in a place other than your finger, here are some key things to remember on when to use and when to not use AST. Before making a decision on

if to use alternate site testing, please speak with your healthcare provider on if this method will work for you and help you find an approved meter. Not all blood glucose meters are approved for alternate site testing. Follow the instructions provided with your testing system for traditional and alternate site testing. Products like Accu-Chek’s FastClix may also mention if their device is approved for such use. Patients need to check their product’s labeling for approved AST sites. For example, Accu-Chek FastClix is only approved for alternate testing on the ball of the thumb, the ball of the little finger, the underside of the forearm, the upper arm and the top of the forearm. It’s also important to note that alternative site testing is not recommended for pregnant women.

When It’s Okay to Use AST

● Before a meal

● When fasting or when your blood sugar is stable

● Near bedtime

When to Refrain from AST

● When taking insulin, when glucose may be falling quickly.

● After exercise, when glucose may be falling quickly.

● After meals, when glucose may be rising quickly.

● If you are sick or stressed.

Key Takeaways:

● Alternate Site Testing (AST) is testing blood glucose in areas other than the fingertips.

● Alternate sites include the forearm, palms, legs, upper arm and stomach.

● AST can be just as accurate as traditional testing at the fingertips if blood sugar is stable, but may not be if glucose is rising or falling quickly.

● There are blood glucose meters that are approved for alternate site testing.

This article is sponsored by Roche Diabetes Care, a Founding Partner of Beyond Type 2. 

WRITTEN BY T'ara Smith, MS, Nutrition Education, POSTED 04/06/21, UPDATED 10/10/22

T’ara was diagnosed with type 2 diabetes in July 2017 at the age of 25. Since her diagnosis, she focused her academic studies and career on diabetes awareness and living a full life with it. She’s excited to have joined the Beyond Type 1 team to continue her work. Two years later, T'ara discovered she'd been misdiagnosed with type 2 and actually has latent autoimmune diabetes in adults (LADA). Outside the office, T’ara enjoys going to the movies, visiting parks with her dog, listening to BTS and cooking awesome healthy meals. T’ara holds an MS in Nutrition Education from American University.