Why Your Glucometer Reading Might Be Higher Than a Lab Test

Managing blood sugar levels is a critical part of diabetes care and for some with chronic kidney disease (CKD). If you're monitoring your blood glucose at home using a glucometer, you might have noticed some differences when comparing those readings to the results you get from a blood test at a lab. This discrepancy can be concerning, but it’s important to understand the factors that can contribute to these differences. Knowing why your home reading might be higher than your lab results can help you better manage your health.

Understanding the Difference

Before does alcohol sugar affect blood sugar diving in, let's clarify the key difference between these two testing methods. A glucometer measures blood glucose levels why does blood sugar go up at night in capillary blood, which is a small sample of blood taken from your fingertip. In contrast, a lab test typically uses venous blood, drawn from a vein, usually in your arm. This may seem like a small difference, but there are physiological reasons why these readings can vary. Venous blood typically provides a more stable measurement.

Measurement Type	Blood Source	Method	Accuracy	Common Usage
Glucometer	Capillary	Small blood drop on test strip	May vary	Daily home monitoring
Lab Test	Venous	Blood sample analyzed in lab	Generally more accurate	Infrequent diagnosis or check up

Why Might the Glucometer Show a Higher Reading?

Here are the key reasons your glucometer may report higher blood glucose levels compared to lab test:

1. Capillary vs. Venous Blood Differences: Immediately after eating, glucose levels can fluctuate faster in capillary blood than venous blood. Therefore, capillary blood (used by a glucometer) may briefly show a higher glucose level during peak periods of postprandial glucose elevation. A lab test performed on venous blood, particularly a fasting sample, often reflects a steadier average and will most likely read lower if drawn a good bit of time following a meal.

2. Proper Usage and Technique: Inaccurate use of the glucometer is a very common cause of discrepancies. This can include:

   • Not washing hands properly: Residue of food or sugary substances on the fingers can contaminate the blood sample, resulting in higher readings.
   • Using expired test strips: Test strips have an expiration date, and using old ones can lead to inaccurate results.
   • Not using enough blood: Insufficient blood on the test strip can lead to a false higher or inaccurate reading.
   • Incorrect coding: Not matching the meter code to the lot number of the test strips, depending on your meter.

3. The Dawn Phenomenon: This physiological event results in an early morning rise in blood sugar, likely due to hormonal shifts. The glucometer readings taken soon after waking up will likely show higher results than lab results drawn later in the day. This phenomenon may not have been in place by the time a patient gets their blood draw at the lab.

4. Stress: During periods of physical or mental stress, the body releases hormones that can elevate glucose levels. If you are stressed when taking the reading with your glucometer, it could temporarily result in higher results compared to a less stressful visit to the lab.

5. Meter Calibration: Glucometers are not perfect 174 blood sugar devices; they are calibrated with standards and generally vary with certain ranges (often within +/- 15%). Most glucometers need to be coded with specific numbers found on each test strip lot. Ensure you are doing this correctly, or that your meter will auto-adjust for lot numbers. Also, meters should undergo a quality control test per the manufacturers instruction manuals.

6. Dehydration: Being dehydrated will make your blood more concentrated, potentially leading to higher glucose results from the capillary sampling done on the glucometer.

7. Peripheral Sampling: Sampling from the fingertips involves an area that is more readily exposed to temperature fluctuations and trauma than sampling from the veins in your arm used during lab draws. Extreme temperature exposure, both hot and cold, can result in higher glucometer readings, as well as minor abrasions to fingertips.

---

Practical Steps for Accurate Glucometer Readings

Getting reliable readings from your glucometer is essential for effective blood glucose management. Here's a step-by-step guide:

1. Wash Your Hands Thoroughly: Wash your hands with warm water and soap, ensuring that all food residue and possible sugars are completely washed away. Dry your hands completely. Do not use hand sanitizers.
2. Use Fresh Test Strips: Check the expiration date on the test strip container and dangerous low blood sugar levels ensure it’s not expired, and that the bottle is closed completely after removing strips to prevent moisture damage.
3. Obtain a Proper Blood Sample: Prick the side of your finger to minimize pain and gently squeeze out a small blood drop. Make sure to get an appropriate amount on the test strip without smearing the blood, or needing a second blood drop for testing.
4. Calibrate and Check Meter Quality: Make sure the meter is calibrated and/or coded correctly per the instructions, and that control solution test passes each time before you run a sample with your blood.
5. Keep a Log: Write down the time, circumstances, and readings taken on your meter to track your sugar patterns. Be sure to note if you had just eaten or if you are experiencing stress. This best way to lower blood sugar without insulin is the data your healthcare professional uses.

Troubleshooting Discrepancies

• Check the Control Solution Test: Most glucometers come with control solutions for quality control checks. Make sure your meter and strips are still valid and calibrated.
• Review Technique with Your Doctor: Discuss your testing method with your doctor or diabetes educator. They can observe your technique and identify potential issues.
  • Monitor patterns: Compare and record your glucometer readings during the day. If you tend to see higher numbers on your meter, compare this with your lab testing results.

---

When to Be Concerned and When to Seek Medical Advice

While some variability between glucometer and lab results is normal, consistently large discrepancies may warrant a closer look. Seek medical advice if:

• Your glucometer readings are consistently and significantly higher (or lower) than your lab results, specifically outside the clinically accepted range.
• You notice unexplained spikes or dips in your blood glucose readings.
• You feel unwell or have any concerning symptoms, despite what your glucometer is showing.
• You are having trouble understanding the proper use of your meter and test strips.

Scenario	Action
Consistently high glucometer results	Consult your doctor or healthcare provider
Unexplained reading fluctuations	Monitor trends; consider consulting your doctor
Persistent abnormal results with symptoms	Seek immediate medical attention

It's also good to remember that, in general, lab tests performed on venous blood samples are considered to be more accurate than capillary blood samples used on glucose meters. They represent a good overview of longer range glucose values than what the home meter can capture.

---

Conclusion

While it’s normal for glucometer readings to differ slightly from lab tests, a good understanding of the reasons for these differences can prevent anxiety and empower you to manage your blood sugar more effectively. Always ensure you are using your glucometer correctly and consult your doctor if you have concerns or questions about your results. This information should not replace advice from your healthcare provider, and they should always be consulted when making care decisions regarding diabetes and/or chronic kidney disease management. Taking care in how you monitor at home is the key to reliable data.

Today’s instructional video will walk you through the different memory modes on your POGO Automatic. The POGO Automatic's memory can store up to 500 results, including glucose averages for different time frames and meal markers. Before starting, ensure the meter is turned off, then briefly press the "M" button to cycle through different data views. The first screen displays your last test result, along with the time, date, and meal marker. Pressing either scroll button reveals the logbook, showing time, date, and meal marker for each result. Control solution test results are marked with green pass or red fail symbols. Pressing the "M" button again shows average glucose levels for the last 7 days, 14 days, 30 days, and 90 days, along with the number of results used for calculation. Another press of the "M" button displays glucose averages by meal marker. To exit memory mode, simply press the power button or allow POGO Automatic to turn off on its own. Learn more: Need help with your POGO Automatic? Our customer support team is available to answer your questions at 1-855-IMI-POGO (464-7646) Not yet a customer? Learn more about POGO Automatic at www.presspogo.com. Subscribe to the channel: #POGOautomatic #glucosemonitoring #tutorial