Common Mistakes to Avoid When Checking Your Blood Glucose (BG) Managing blood glucose levels is a critical aspect of diabetes management. Regularly ch...

Common Mistakes to Avoid When Checking Your Blood Glucose (BG)

Managing blood glucose levels is a critical aspect of diabetes management. Regularly checking your blood glucose (BG) provides essential data to make informed decisions about diet, exercise, and medication. However, incorrect techniques or overlooked factors can lead to inaccurate readings, hindering effective diabetes management. This article outlines common mistakes to avoid when checking your blood glucose, ensuring you obtain reliable results to help you stay healthy.

1. Skimping on Hand Hygiene

One of the most frequent and easily avoidable errors is neglecting proper hand hygiene.

Why it matters:

Contaminants, like food residue or lotions, on your fingers can significantly skew blood glucose readings. Even trace amounts of sugar from fruit or honey can falsely elevate your blood glucose level, leading to unnecessary anxiety or incorrect insulin dosing.

How to avoid it:

Always wash your hands thoroughly with warm water and soap before testing. Ensure your hands are completely dry, as water can also dilute the blood sample. Avoid alcohol-based sanitizers immediately before testing, as some contain ingredients that may affect the reading. If soap and water aren't available, use pre-moistened, individually wrapped alcohol wipes specifically designed for diabetes testing and allow the alcohol to evaporate completely before proceeding.

Example:

Imagine you just ate an apple and decide to check your blood glucose without washing your hands. Residual apple juice containing fructose sticks to your fingertip. The glucometer reads higher than your actual blood glucose level because of the external sugar contamination. Washing and drying your hands removes these contaminants, ensuring an accurate reading.

2. Improper Blood Sample Size

Getting an adequate blood sample size is crucial for an accurate blood glucose reading. Both too little and, less commonly, too much blood can affect the results.

Why it matters:

Insufficient blood may lead to error messages on the glucometer or inaccurate, artificially low readings. Too much blood, although less common, can also sometimes lead to inaccurate readings.

How to avoid it:

Use the Correct Lancing Device Setting: Adjust the depth setting on your lancing device according to your skin thickness. Thinner skin (e.g., in children or older adults) requires a shallower setting.
Rotate Lancing Sites: Regularly change the finger you use for testing to prevent calluses and improve blood flow. Recommended sites are the sides of the fingertips.
Apply Gentle Pressure: After lancing, gently squeeze the finger towards the puncture site to encourage a sufficient drop of blood to form. Avoid excessive squeezing, which can dilute the sample with tissue fluid, leading to an inaccurate result.
Ensure Proper Application: Touch the edge of the test strip to the blood drop and allow the strip to draw the blood in via capillary action. Do not smear or force the blood onto the strip.
Heed Glucometer Warnings: Pay attention to error messages indicating insufficient blood. If this happens, use a fresh test strip and re-lance a different finger.

Example:

Suppose you're using a lancet device set too shallow. You get a tiny pinprick and a very small bead of blood. Instead of re-lancing, you force the tiny drop onto the test strip. The glucometer may give an "error" message or provide an inaccurate, falsely low reading because it didn't receive enough blood for the analysis. Re-lancing a different finger at the correct depth ensures an adequate sample size.

3. Using Expired or Improperly Stored Test Strips

Test strips are sensitive to environmental conditions, and using expired or improperly stored strips can significantly compromise the accuracy of blood glucose readings.

Why it matters:

Test strips contain enzymes that react with glucose in the blood. Over time or when exposed to humidity, extreme temperatures, or direct sunlight, these enzymes can degrade, leading to unreliable results. Expired strips are also prone to inaccurate readings.

How to avoid it:

Check Expiration Dates: Always check the expiration date on the test strip vial before use. Discard expired strips immediately.
Proper Storage: Store test strips in their original, tightly closed container in a cool, dry place away from direct sunlight and humidity. Avoid storing them in bathrooms or kitchens, where temperature and humidity fluctuate.
Avoid Damaged Strips: Do not use test strips that appear damaged, discolored, or warped. These are likely to be compromised.
Control Solution Testing: Periodically (e.g., when opening a new vial of test strips) use a control solution provided by the glucometer manufacturer to verify the accuracy of the strips and the meter. This involves using a solution with a known glucose concentration and comparing the result to the expected range provided by the manufacturer.

Example:

You find an old vial of test strips in your medicine cabinet. The expiration date is blurry, but you decide to use them anyway. Because the enzymes in the strips have degraded over time, your blood glucose reading is significantly lower than your actual level. This could lead you to consume unnecessary sugar, potentially causing a blood glucose spike later. Always using fresh, properly stored strips ensures accurate readings.

4. Not Calibrating the Glucometer Regularly

Glucometers require regular calibration to maintain accuracy. Calibration ensures that the meter is reading blood glucose levels correctly relative to a known standard.

Why it matters:

Over time, glucometers can drift out of calibration due to factors like wear and tear, temperature changes, or manufacturing variations. This can lead to consistent inaccuracies in your blood glucose readings, making it difficult to manage your diabetes effectively.

How to avoid it:

Follow Manufacturer's Instructions: Refer to the glucometer's user manual for specific calibration instructions.
Control Solution Testing: Use control solutions regularly (as described in section 3) to check the meter's accuracy.
Compare with Lab Results: Periodically (e.g., during doctor's appointments), compare your glucometer readings to laboratory blood glucose tests performed by a healthcare professional. This provides a benchmark to assess the accuracy of your meter.
Recalibrate if Necessary: If control solution testing or comparison with lab results reveals significant discrepancies, recalibrate the meter according to the manufacturer's instructions. Some meters automatically calibrate; others require manual calibration using a code or chip provided with the test strips.

Example:

You've been using the same glucometer for years without ever checking its calibration. Over time, the meter has drifted and is now consistently reading 20 mg/dL lower than your actual blood glucose levels. This means you're often taking too much insulin, which can lead to dangerous hypoglycemic episodes. Regular calibration helps prevent such scenarios.

5. Incorrect Coding of Glucometer (If Required)

Some older glucometers require manual coding to match the specific batch of test strips being used. This coding ensures that the meter interprets the signals from the test strip correctly. While many modern glucometers automatically code, this is still a relevant consideration for older models.

Why it matters:

If the glucometer is not correctly coded to match the test strip, the readings will be inaccurate. Mismatched coding can result in readings that are significantly higher or lower than the actual blood glucose level.

How to avoid it:

Check for Coding Requirements: Determine whether your glucometer requires coding. Refer to the user manual if you're unsure.
Verify Code Numbers: When opening a new vial of test strips, check the code number printed on the vial.
Enter Code Carefully: If manual coding is required, carefully enter the code number into the glucometer according to the manufacturer's instructions. Ensure the code is entered correctly.
Automatic Coding (if applicable): For meters with automatic coding, verify that the meter is properly recognizing and accepting the new test strip batch.

Example:

You open a new box of test strips, but you forget to change the code on your glucometer to match the new batch. As a result, your readings are consistently 30 mg/dL higher than your actual blood glucose level. This leads you to unnecessarily restrict your carbohydrate intake, resulting in frequent feelings of weakness and fatigue. Ensuring the glucometer is correctly coded eliminates this issue.

6. Ignoring Environmental Factors

Environmental conditions, such as temperature and altitude, can sometimes affect blood glucose meter accuracy.

Why it matters:

Extreme temperatures can affect the chemical reactions within the test strip, leading to inaccurate readings. High altitude can also affect the readings, particularly for older glucometers.

How to avoid it:

Operate Within Temperature Range: Use the glucometer and test strips within the temperature range specified by the manufacturer. Avoid testing in extremely hot or cold environments.
Acclimatize to Altitude Changes: If traveling to high altitudes, allow the glucometer to acclimatize to the new environment for at least 20 minutes before testing. Some meters may require specific adjustments for altitude; consult the user manual.
Shield from Direct Sunlight: Avoid testing in direct sunlight, as this can affect the temperature of the test strip and the meter.

Example:

You're hiking in the mountains at high altitude and decide to check your blood glucose. You take a reading immediately after arriving, without allowing your meter to adjust to the altitude. The meter displays a falsely high reading, leading you to inject more insulin than necessary. Giving the meter time to acclimatize before testing would have provided a more accurate result.

7. Neglecting Meter Maintenance

Regular maintenance of your glucometer is essential for ensuring its accuracy and longevity.

Why it matters:

Dust, dirt, and blood can accumulate on the glucometer, potentially interfering with its sensors and affecting its performance. Battery issues can also lead to inaccurate readings or meter malfunction.

How to avoid it:

Clean Regularly: Clean the glucometer regularly according to the manufacturer's instructions. Use a soft, lint-free cloth dampened with a mild cleaning solution to wipe down the exterior of the meter. Avoid getting liquid inside the meter.
Check and Replace Batteries: Check the battery level regularly. Replace batteries when the meter indicates low battery power or when the display becomes dim or erratic. Use the correct type of battery specified by the manufacturer.
Store Properly: Store the glucometer in its case or pouch when not in use to protect it from dust, dirt, and physical damage.

Example:

You never clean your glucometer, and over time, a layer of dust and dried blood accumulates around the test strip port. This buildup interferes with the meter's ability to properly read the test strip, resulting in consistently inaccurate readings. Regular cleaning would prevent this issue.

8. Ignoring Fasting Recommendations (if applicable)

For fasting blood glucose tests, adhering to the prescribed fasting period is essential for obtaining accurate results.

Why it matters:

Consuming food or beverages (other than water) before a fasting blood glucose test can artificially elevate blood glucose levels, leading to incorrect diagnosis or treatment decisions.

How to avoid it:

Follow Fasting Guidelines: Adhere strictly to the fasting guidelines provided by your healthcare provider. Typically, this involves refraining from eating or drinking anything other than water for at least 8-12 hours before the test.
Medication Considerations: Discuss with your healthcare provider whether you should take your diabetes medications as usual on the morning of a fasting blood glucose test. Some medications may need to be adjusted or withheld to ensure accurate results.
Schedule Test Appropriately: Schedule the fasting blood glucose test for a time that is convenient and allows you to comfortably complete the fasting period without undue hunger or discomfort.

Example:

You're scheduled for a fasting blood glucose test in the morning. However, you're feeling hungry, so you eat a small snack before going to the lab. This elevates your blood glucose level, resulting in a falsely high fasting blood glucose reading. The doctor may misinterpret this result as an indication that your diabetes is poorly controlled. Following the fasting guidelines ensures accurate results.

9. Failing to Log Results Consistently

Inconsistent or incomplete logging of blood glucose results can hinder effective diabetes management.

Why it matters:

Regular logging of blood glucose results, along with information about diet, exercise, medications, and other relevant factors, provides valuable insights into how your blood glucose levels are affected by various influences. This information helps you and your healthcare provider make informed decisions about your treatment plan.

How to avoid it:

Use a Consistent Method: Choose a logging method that works best for you, whether it's a paper logbook, a smartphone app, or an online diabetes management platform.
Record All Relevant Information: Record not only the blood glucose reading but also the date, time, meal details, exercise activity, medications taken, and any other factors that might influence your blood glucose levels (e.g., stress, illness).
Be Consistent: Make logging blood glucose results a regular habit. Test at the same times each day and log the results immediately after testing.
Review Data Regularly: Regularly review your blood glucose logs with your healthcare provider to identify patterns, trends, and areas for improvement in your diabetes management.

Example:

You sporadically check your blood glucose and occasionally jot down the results on a scrap of paper. However, you often forget to record important details, such as what you ate or whether you exercised. As a result, you have no clear picture of how different factors are affecting your blood glucose levels, making it difficult to make informed decisions about your diet and medications. Consistent logging provides the data you need for effective diabetes management.

10. Ignoring Meter Error Messages

Glucometers often display error messages indicating a problem with the test. Ignoring these messages can lead to inaccurate results.

Why it matters:

Error messages alert you to potential issues that could affect the accuracy of the blood glucose reading, such as an insufficient blood sample, a damaged test strip, or a meter malfunction.

How to avoid it:

Read and Understand Error Messages: Familiarize yourself with the meaning of different error messages displayed by your glucometer. Consult the user manual for a list of error codes and their explanations.
Take Action: When an error message appears, take appropriate action. This may involve re-testing with a fresh test strip, checking the battery level, cleaning the meter, or contacting the manufacturer for assistance.
Do Not Ignore: Do not ignore error messages or attempt to override them. This could lead to inaccurate readings and potentially dangerous consequences.

Example:

You insert a test strip into your glucometer, but the meter displays an "E-4" error message. You ignore the message and proceed to apply a blood sample anyway. The meter provides a blood glucose reading, but it's likely to be inaccurate due to the underlying problem indicated by the error message. Addressing the error message before testing ensures more reliable results.

Conclusion

Accurate blood glucose monitoring is paramount for effective diabetes management. By avoiding these common mistakes, you can ensure that your blood glucose readings are reliable, allowing you to make informed decisions about your diet, exercise, and medication. Regular monitoring, combined with proper technique and understanding of your glucometer, will empower you to proactively manage your diabetes and lead a healthier life. Remember to consult with your healthcare provider for personalized guidance and support in managing your blood glucose levels.