How to Check Blood Sugar Levels at Home

Managing diabetes starts with accurate blood sugar monitoring at home. Whether you use a traditional glucose meter or a continuous glucose monitor (CGM), knowing how to test your levels is essential for better health.

Key Takeaways

• Glucose Meters: Require a finger prick and test strips for single-point readings. Costs range from $20–$80 for meters and $0.25–$1 per test strip. Look for features like memory storage and fast results.
• Continuous Glucose Monitors (CGMs): Use a sensor under the skin to track glucose levels continuously. They provide real-time data, trend insights, and fewer finger pricks but are more expensive. Medicare and many insurance plans now cover CGMs.
• When to Test: Common times include before meals, 2 hours after eating, before exercise, and at bedtime. Testing frequency depends on your diabetes type and treatment plan.
• Target Ranges: For most adults with diabetes, aim for 80–130 mg/dL before meals and less than 180 mg/dL after meals.
• Troubleshooting: Always wash hands before testing, store supplies properly, and consult your doctor if readings are consistently too high or low.

Feature	Glucose Meter	CGM
Measurement Frequency	Single point in time	Every few minutes
Method	Finger prick blood sample	Sensor under the skin
Trend Information	No	Yes
Alerts for Levels	No	Real-time CGMs only
Finger Sticks Needed	Every test	Reduced or eliminated

Start testing by choosing the right tool, following proper techniques, and recording your results. Accurate monitoring helps you and your healthcare provider adjust your care plan for better health outcomes.

How to Measure Your Blood Sugar

Tools You Need for Home Blood Sugar Testing

To get accurate blood sugar readings at home, you’ll need the right equipment. Whether you choose a glucose meter or a continuous glucose monitor (CGM) depends on your needs, budget, and how often you plan to track your levels.

Glucometers

A glucose meter (sometimes called a blood glucose meter or BGM) gives you a quick blood sugar reading by analyzing a drop of blood placed on a test strip.

What you’ll need: A meter, test strips, and lancets. Test strips can cost anywhere from less than $0.25 to over a dollar each, depending on the brand. Most meters come with a lancing device designed to minimize discomfort.

Accuracy is key. While U.S.-manufactured meters must meet FDA accuracy standards, research shows that about 66% of approved meters don’t fully meet those standards.

Helpful features to look for: Meters that require only a small blood sample, provide fast results, store readings in memory, and automatically code test strips. Some models also include accessibility options like spoken instructions, larger displays, and easy-to-handle designs for those with dexterity challenges.

Costs to consider: Insurance copays for meters typically range from $20 to $80, but test strip costs can add up quickly. Check with your insurance provider to understand what’s covered, including monthly limits on test strips.

Glucometers are a reliable choice for single-point readings, making them an essential tool for daily diabetes management.

Continuous Glucose Monitors (CGMs)

A continuous glucose monitor tracks your glucose levels every few minutes, offering a more comprehensive view of your blood sugar trends.

How CGMs work: They include a small sensor placed under your skin (usually on your arm or abdomen), a transmitter that sends data wirelessly, and a receiver, which could be a smartphone app, a dedicated device, or even part of an insulin pump. Sensors generally need to be replaced every 7–14 days, though some implantable models last for months.

“CGMs are not just better, more accurate glucometers. They provide real-time data and can predict glucose changes and patterns over time.” – Jyothi Gogineni, MD, Northwestern Medicine endocrinologist

This real-time feedback allows for proactive diabetes management.

Types of CGMs:

• Real-time CGMs continuously send data and can alert you to dangerous glucose levels.
• Intermittently scanned CGMs (like flash glucose monitors) require you to scan the sensor with a compatible device to see your readings.

While real-time CGMs offer more detailed monitoring, they tend to be more expensive.

Benefits of CGMs: People with both Type 1 and Type 2 diabetes who use CGMs often experience fewer low blood sugar episodes and achieve better A1C levels. They also reduce the need for frequent fingerstick tests, though occasional finger pricks may still be necessary to confirm readings before making treatment decisions.

Limitations to be aware of: Since CGMs measure glucose in interstitial fluid (not directly in blood), readings may lag slightly behind actual blood levels. The typical accuracy range for CGMs (measured as MARD) is 9–15%, compared to 5.6–20% for fingerstick glucometers.

While CGMs are generally more expensive than traditional meters, many insurance plans now cover them. Medicare has also removed the requirement for four daily fingerstick tests to qualify for CGM coverage, making these devices more accessible, especially for seniors.

Extra features worth noting: Some CGMs allow data sharing, so caregivers can receive alerts about dangerous glucose levels directly on their smartphones. Many also include trend arrows to show whether your levels are rising, falling, or staying steady.

CGMs provide a deeper understanding of glucose patterns, making diabetes management more efficient and reducing the burden of frequent testing.

Feature	Glucometer	CGM
Measurement frequency	Single point in time	Every few minutes
Method	Finger prick blood sample	Sensor under the skin
Alerts for dangerous levels	No	Real-time CGMs only
Trend information	No	Yes
Finger sticks required	Every test	Reduced or eliminated
Typical accuracy (MARD)	5.6–20%	9–15%

Choose the tool that fits your personal diabetes management goals before diving into the steps for testing.

With the right equipment in hand, you’re ready to start checking your blood sugar step by step.

How to Check Your Blood Sugar Step by Step

Getting a precise blood sugar reading requires following the correct steps in order. With your device ready, here’s how to test accurately.

Getting Ready to Test

Before starting, gather everything you need – your meter or CGM, test strips, lancets, and any other supplies.

Wash your hands thoroughly with soap and warm water, then dry them completely. If your hands are cold, warming them can improve blood flow. Avoid using alcohol pads to clean your skin, as they don’t effectively remove sugar residue. Make sure your hands are completely dry, as even slight moisture can dilute your blood sample.

Double-check that your meter is charged. Look at the expiration date on your test strips and keep their container sealed tightly when not in use – expired strips can lead to inaccurate results.

Testing with a Glucometer

Follow these steps to get an accurate reading with a glucometer:

If it’s your first time using the meter, follow the setup instructions provided by the manufacturer. Always use the correct test strips for your specific meter, as strips from different brands are not interchangeable.

Insert a test strip into the meter. Use the lancing device on the side of your fingertip to get a small drop of blood. Be careful not to touch the strip with damp hands, as moisture can interfere with the results. Most meters will turn on automatically when you insert the strip.

Place the blood drop on the designated area of the test strip. The meter will draw the blood into the strip and process the sample. In just a few moments, your result will appear on the screen.

“Monitoring your blood sugar is the most important thing you can do to manage diabetes.” – Diabetes | CDC

Remember, never share your blood sugar monitoring tools with anyone else. This helps reduce the risk of spreading bloodborne infections.

Testing with a CGM

For continuous glucose monitoring (CGM), follow these steps:

Insert the sensor using the applicator. Most sensors are placed on the belly or arm, but check the instructions for your specific model, as placement methods can vary.

Allow the sensor to warm up. Many CGMs need 30 minutes to 2 hours to calibrate and start showing data.

If calibration is required, complete it as directed. Then, set alarms on your receiver or smartphone app for high and low glucose levels. Your glucose levels will update in real time on your app, receiver, or insulin pump.

In 2024, new advancements in CGM technology were approved by the FDA, including Dexcom’s Stelo Glucose Biosensor System and Abbott’s Lingo and Libre Rio models, which are available over the counter.

To ensure you’re using your CGM safely and effectively, consult with a certified diabetes care and education specialist (CDCES). They can help you interpret the data and adjust your care plan as needed.

Cleaning Up After Testing

Once you’re done testing, proper cleanup is key to maintaining accuracy for future readings.

Dispose of used supplies carefully. Place lancets and test strips in a sharps or puncture-resistant container. Never throw loose lancets into regular trash, as they can cause injuries.

Clean your glucometer with a damp cloth, and follow the manufacturer’s cleaning instructions for CGMs.

Store your supplies correctly. Test strips should remain in their original, sealed container, and all devices should be kept in a cool, dry place, away from extreme temperatures. Proper storage helps maintain accuracy and extends the lifespan of your equipment.

Replace CGM sensors as recommended. Most sensors last 7 to 15 days, but some implantable options can last for months. Keep track of replacement dates by marking them on your calendar.

When to Test and Understanding Your Results

Managing diabetes effectively means knowing when to test and understanding your results. Once you’ve got the hang of testing techniques, the next step is figuring out how often to test.

How Often You Should Test

How often you need to test depends on the type of diabetes you have, the medications you take, and your doctor’s advice. Testing routines can vary widely based on individual treatment plans.

For type 1 diabetes, testing your blood sugar at least four times a day is recommended. Since your body doesn’t produce insulin, your blood sugar levels can fluctuate unpredictably, requiring frequent checks.

For type 2 diabetes, most people only need to test once or twice a day. If your blood sugar is stable and well-managed, you might only need to check a few times a week or even less often.

However, there are situations where more frequent testing is necessary. You should test more often if you’re using insulin, are pregnant, have trouble meeting your blood sugar goals, experience frequent lows, don’t feel symptoms during lows, are sick, or recovering from surgery.

Certain times of the day are particularly helpful for testing, especially if you’re on insulin. These include:

• When you wake up (to check fasting glucose)
• Before meals
• Two hours after starting a meal
• Before and after exercise
• Before bedtime

If you notice unusual symptoms, test right away. Many people with diabetes don’t feel symptoms of high blood sugar until levels reach 250 mg/dL or higher. On the other hand, low blood sugar symptoms often appear when levels drop below 70 mg/dL.

Your doctor or diabetes educator can help you decide how often to test and create a schedule tailored to your needs.

What Your Numbers Mean

Once you’ve established your testing routine, the next step is understanding what your results mean. Blood glucose targets are personalized based on factors like how long you’ve had diabetes, your age, other health conditions, and your overall treatment goals.

The American Diabetes Association offers general blood sugar targets for most nonpregnant adults with diabetes:

Time	Target Range
Before meals	80–130 mg/dL
1–2 hours after starting a meal	Less than 180 mg/dL

For comparison, normal blood sugar levels for people without diabetes typically range from 70–99 mg/dL. Readings between 100–125 mg/dL may indicate prediabetes, which comes with up to a 50% chance of developing type 2 diabetes within 5–10 years.

High blood sugar, or hyperglycemia, is generally defined as levels above 180 mg/dL for people with diabetes. If your readings consistently stay high, talk to your doctor. You might need to adjust your medication or make other changes to your treatment plan.

Low blood sugar, or hypoglycemia, is when your levels drop below 70 mg/dL. If this happens, consume 15 grams of carbohydrates, wait 15 minutes, and check your levels again. If they’re still low, repeat the process.

Keeping track of your readings can help you spot patterns and understand how different factors – like meals, exercise, medications, stress, or illness – affect your blood sugar. Record details such as the timing of your tests, what you ate, your physical activity, and any other relevant factors.

Bring these records to your doctor’s appointments to review your progress and adjust your treatment plan if needed. If your blood sugar stays above your target range for several days without an obvious cause, reach out to your healthcare provider.

Fixing Problems and Helpful Tips

Getting accurate blood sugar readings is crucial for managing diabetes effectively, and troubleshooting plays a big role in keeping things on track. Even with the best efforts, testing can sometimes feel tricky. Tackling common challenges and knowing when to reach out for help can make your monitoring routine more reliable.

Solving Common Testing Problems

Even if you’re careful with hand hygiene, inconsistent readings can still happen. One common culprit is finger contamination. Always wash your hands with soap and warm water before testing – alcohol swabs might not remove sugar residue effectively. Make sure you’re using enough blood and handling the meter correctly, as an insufficient sample can throw off results. If a reading seems odd, try rewashing your hands and retesting with a new strip.

Another factor to watch out for is expired or poorly stored test strips. Strips exposed to extreme heat or cold can lead to inaccurate readings.

For issues like power or strip errors, check the battery, restart the meter, and ensure the strip is inserted correctly. If your meter has auto-coding errors, restarting it, using a fresh strip, and letting the device adjust to room temperature can often fix the problem.

Struggling to get enough blood for testing? Washing your hands with warm water can improve circulation, and using the side of your fingertip may help. Make sure the puncture is deep enough, but avoid squeezing the finger too hard.

These tips apply to traditional meters, but continuous glucose monitors (CGMs) come with their own set of challenges. If CGM readings don’t match fingerstick results, recalibrate the device and avoid putting pressure on the sensor, as that can affect accuracy. If the adhesive starts peeling, try securing it with tape. If problems persist, it might be time to consult your healthcare provider.

Remember, glucose meters can vary up to 20% from actual levels. Certain medications, like acetaminophen, high doses of vitamin C, salicylic acid, and some prescription drugs, may also interfere with readings.

To ensure your meter is accurate, bring it with you when getting a lab glucose test. Compare the lab results with your meter’s reading. Regular use of control solutions can also confirm that your meter and strips are working as they should. If one device consistently gives poor results, consider switching to a different one.

“To check the accuracy of your meter, bring it with you when you have your blood glucose read in the laboratory. After testing there, check the number against your meter’s finding. If you are concerned about the accuracy of your meter, ask your doctor for recommendations.” – Healthgrades Editorial Staff

When to Call Your Doctor

If troubleshooting doesn’t resolve your issues, it’s important to know when to reach out to your doctor.

Contact your healthcare provider if your blood sugar levels stay above 240 mg/dL, even after taking medication, increasing insulin, and drinking more fluids – especially if you detect moderate to large ketones in your urine. Also, call your doctor immediately if you experience symptoms of ketoacidosis or dehydration, such as severe abdominal pain, trouble breathing, or a fruity or acetone-like smell on your breath.

Seek medical advice if you’re dealing with persistent diarrhea or vomiting and can’t keep food or fluids down. Illness can disrupt blood sugar control, and some medications may make it harder to manage. If you notice any new or concerning symptoms, don’t hesitate to ask your doctor for guidance. Having a sick day plan in place with your healthcare team – detailing how often to check your blood sugar and ketones, what medications to take, and when to seek help – can be a lifesaver when you’re unwell.

For CGM users, if readings seem off compared to fingerstick results, wash your hands and retest to verify your meter’s accuracy. Avoid calibrating your CGM when blood sugar levels are low or changing rapidly, as this can lead to further inaccuracies.

Finally, lack of proper education is a common reason for poor self-monitoring. If you’re unsure about testing techniques or need a refresher, don’t hesitate to ask your healthcare team for additional training or advice.

Conclusion

Keeping track of your blood sugar at home is a cornerstone of diabetes management. Whether you’re using a glucometer or a continuous glucose monitor (CGM), consistent monitoring, proper technique, and staying in touch with your healthcare team are key to staying on top of your health.

Simple habits like washing your hands before testing, storing your supplies correctly, and recording results – along with any factors that may have influenced them – can make a big difference. These steps ensure your readings are accurate and reliable.

For most people with diabetes, blood sugar goals are typically 80–130 mg/dL before meals and less than 180 mg/dL one to two hours after eating. If your target is an A1C of under 7%, aim to keep your blood sugar within the target range at least 70% of the time. Accurate and consistent readings provide the data you and your healthcare team need to make timely adjustments that can improve your overall health.

Think of your readings as more than just numbers – they’re a roadmap for better diabetes management. Pay attention to patterns, note what influences your blood sugar, and share these insights with your healthcare provider during regular check-ins. This collaboration helps fine-tune your care plan for the best results.

Don’t forget to bring your meter to appointments and ask questions when you need clarification. Open communication with your healthcare team can lead to better outcomes, fewer complications, and a healthier, more enjoyable life.

With the right tools, proper techniques, and support from your care team, home blood sugar monitoring becomes a powerful tool in managing diabetes. Stay consistent, stay informed, and remember – every reading is a step toward better health.

Frequently Asked Questions