Common Mistakes People Make When Testing Their Blood Glucose

Managing diabetes often involves regularly testing your blood glucose. Accurate blood glucose readings are crucial for making informed decisions about medication, diet, and exercise. However, many people make common mistakes that can lead to inaccurate readings and potentially harmful health outcomes. This article highlights some of the most frequent errors made during blood glucose testing and offers practical tips to avoid them, ensuring you get the most reliable results possible.

Why Accurate Blood Glucose Testing Matters

Before diving into common errors, it's essential to understand why accurate blood glucose testing is critical. Consistent and correct readings allow individuals with diabetes to:

• Adjust insulin dosages effectively.
• Make informed dietary choices.
• Monitor the impact of physical activity.
• Recognize and treat hyperglycemia (high blood sugar) and hypoglycemia (low blood sugar) promptly.
• Collaborate more effectively with their healthcare team to manage their condition.

Inaccurate readings can lead to incorrect dosages of insulin, potentially resulting in serious health complications such as severe hypo- or hyperglycemia, which, if left untreated, can lead to hospitalization.

Common Mistakes in Blood Glucose Testing

Let's explore the common pitfalls to watch out for when testing your blood glucose:

1. Not Washing Your Hands Properly:

   • The Mistake: Many people underestimate the importance of clean hands. Food residue, lotions, or other substances on your fingers can contaminate the blood sample and cause falsely elevated or lowered readings.
   • The Solution: Wash your hands thoroughly with soap and warm water before testing. Dry your hands completely with a clean towel. Avoid using alcohol-based hand sanitizers, as they can affect readings.

2. Using Expired or Incorrectly Stored Test Strips:

   • The Mistake: Test strips have expiration dates. Expired strips may produce inaccurate results. Similarly, improper storage (e.g., in humid environments or direct sunlight) can degrade the chemicals on the strips, affecting their accuracy.
   • The Solution: Always check the expiration date on the test strip vial before using them. Store your test strips in a cool, dry place as indicated on the packaging. Make sure the vial is tightly sealed to prevent moisture exposure.

3. Not Using the Correct Code for the Test Strips:

   • The Mistake: Some blood glucose meters require you to enter a code that matches the specific lot number of your test strips. This code calibrates the meter to the strips. Failing to enter the correct code can lead to significant inaccuracies.
   • The Solution: Check if your meter requires coding. If so, always enter the correct code that is printed on the test strip vial each time you open a new vial. Some newer meters use auto-coding, which eliminates this step.

4. Using an Insufficient Blood Sample:

   • The Mistake: Not applying enough blood to the test strip is a common error. An insufficient sample can lead to an error message or a falsely low reading. People may try to "squeeze" more blood out of their finger, which introduces interstitial fluid that dilutes the sample and compromises accuracy.
   • The Solution: Ensure that you obtain a sufficient blood sample for the test strip. If the first attempt doesn't produce enough blood, use a new lancet to prick a different spot on your finger. Avoid squeezing the finger forcefully.
5. 

   Not Pricking Deep Enough:

   • The Mistake: Many people are hesitant to prick their finger deeply enough, leading to an inadequate blood sample. This is especially true for those who are new to testing.
   • The Solution: Adjust the depth setting on your lancing device to ensure a sufficient prick. Consider rotating your pricking sites to avoid developing calluses, which can make it more difficult to obtain a blood sample.

6. Ignoring the Meter's Quality Control Checks:

   • The Mistake: Most meters come with control solutions that allow you to test the meter's accuracy. Ignoring these quality control checks can mean you're relying on a meter that is providing inaccurate results.
   • The Solution: Periodically use the control solutions to ensure your meter is functioning correctly. Consult your meter's manual for instructions on how to perform a control solution test. Perform this test when you first get the meter, when you open a new vial of test strips, and if you suspect the meter is not working correctly.

7. Testing in the Wrong Location:

   • The Mistake: While some meters allow for alternate site testing (e.g., forearm, thigh), these sites may not be as accurate, especially when blood glucose levels are changing rapidly (e.g., after a meal or exercise).
   • The Solution: For the most accurate results, especially when you need to make immediate treatment decisions, test on your fingertip. Your fingertips have more capillary blood flow and will reflect changes in blood glucose more quickly.

8. Not Maintaining Your Meter:

   • The Mistake: Meters can accumulate dust and debris that can affect their performance. Neglecting to clean and maintain your meter can lead to inaccurate readings.
   • The Solution: Clean your meter regularly according to the manufacturer's instructions. Usually, this involves wiping it down with a soft, slightly damp cloth. Avoid using harsh chemicals or solvents.

9. Dehydration:

   • The Mistake: Insufficient fluid intake can impact the concentration of glucose in your blood. Dehydration can lead to falsely elevated blood glucose readings.
   • The Solution: Stay adequately hydrated, especially before testing your blood glucose. Proper hydration helps ensure that blood samples are accurate reflections of your glucose levels.

10. Extreme Temperatures:

    • The Mistake: Exposing your meter and testing supplies to extreme temperatures, either hot or cold, can negatively impact their functionality and accuracy.
    • The Solution: Store your meter and test strips at room temperature, away from direct sunlight, heat, or excessive cold. Refer to the manufacturer's guidelines for specific temperature ranges.

Troubleshooting Inaccurate Blood Glucose Readings

If you consistently experience readings that don't align with how you feel or your usual patterns, consider the following steps:

• Repeat the Test: Retest your blood glucose immediately.
• Check the Meter and Strips: Ensure they are within their expiration dates and stored properly.
• Perform a Control Solution Test: To verify the meter's accuracy.
• Consult Your Healthcare Provider: If issues persist, discuss them with your doctor or diabetes educator, who can help troubleshoot and adjust your management plan.

The Importance of Education and Training

Proper blood glucose testing requires education and ongoing reinforcement. Individuals newly diagnosed with diabetes should receive comprehensive training from a certified diabetes educator (CDE) or other healthcare professional. Even those who have been managing diabetes for years can benefit from periodic refresher courses to ensure they are using the most up-to-date techniques and technology.

Using Continuous Glucose Monitoring (CGM) Systems

While not a direct replacement for traditional blood glucose testing in all situations, continuous glucose monitoring (CGM) systems offer many advantages, including:

• Real-time glucose readings.
• Trend arrows showing the direction and speed of glucose changes.
• Alerts for high and low glucose levels.
• Reduced need for frequent fingersticks.

However, CGMs require periodic calibration using fingerstick blood glucose readings, so understanding and avoiding the common mistakes outlined above is still important.

Key Takeaways

Mistake	Solution
Not washing hands properly	Wash hands with soap and water; dry thoroughly.
Expired/incorrectly stored strips	Check expiration dates; store in a cool, dry place.
Incorrect code for strips	Enter the correct code from the strip vial.
Insufficient blood sample	Use a new lancet and a different pricking site.
Not pricking deep enough	Adjust the depth setting on your lancing device.
Ignoring meter quality checks	Perform control solution tests regularly.
Testing in the wrong location	Use fingertips for the most accurate results.
Not maintaining your meter	Clean the meter regularly.
Dehydration	Stay adequately hydrated before testing.
Extreme temperatures	Store meter and supplies at room temperature.

By understanding and avoiding these common mistakes when testing blood glucose, individuals with diabetes can achieve more accurate readings and better manage their health, ultimately improving their quality of life. Consistent accuracy in testing empowers individuals to make well-informed decisions about their daily diabetes management and strengthens their partnership with their healthcare team.