Regular blood sugar monitoring is the most important thing you can do to manage type 1 or type 2 diabetes. You’ll be able to see what makes your numbers go up or down, such as eating different foods, taking your medicine, or being physically active. With this information, you can work with your health care team to make decisions about your best diabetes care plan. These decisions can help delay or prevent diabetes complications such as heart attack, stroke, kidney disease, blindness, and amputation. Your doctor will tell you when and how often to check your blood sugar levels.

Most blood sugar meters allow you to save your results and you can use an app on your cell phone to track your levels. If you don’t have a smart phone, keep a written daily record like the one in the photo. You should bring your meter, phone, or paper record with you each time you visit your health care provider.

Make Friends With Your Numbers

Sometimes having high blood sugar can feel like a test you didn’t pass. But numbers are just numbers. Think of them instead as information. Did a certain food or activity make your levels go up or down? Armed with that knowledge, you can make adjustments and get closer to your target range more often.

How to Use a Blood Sugar Meter

There are different kinds of meters, but most of them work the same way. Ask your health care team to show you the benefits of each. In addition to you, have someone else learn how to use your meter in case you’re sick and can’t check your blood sugar yourself.

Below are tips for how to use a blood sugar meter.

1. Make sure the meter is clean and ready to use.
2. After removing a test strip, immediately close the test strip container tightly. Test strips can be damaged if they are exposed to moisture.
3. Wash your hands with soap and warm water. Dry well. Massage your hand to get blood into your finger. Don’t use alcohol because it dries the skin too much.
4. Use a lancet to prick your finger. Squeezing from the base of the finger, gently place a small amount of blood onto the test strip. Place the strip in the meter.
5. After a few seconds, the reading will appear. Track and record your results. Add notes about anything that might have made the reading out of your target range, such as food, activity, etc.
6. Properly dispose the lancet and strip in a trash container.
7. Do not share blood sugar monitoring equipment, such as lancets, with anyone, even other family members. For more safety information, please see Infection Prevention during Blood Glucose Monitoring and Insulin Administration.
8. Store test strips in the container provided. Do not expose them to moisture, extreme heat, or cold temperatures.

Recommended Target Ranges

The following standard recommendations are from the American Diabetes Association (ADA) for people who have diagnosed diabetes and are not pregnant. Work with your doctor to identify your personal blood sugar goals based on your age, health, diabetes treatment, and whether you have type 1 or type 2 diabetes.

Your range may be different if you have other health conditions or if your blood sugar is often low or high. Always follow your doctor’s recommendations.

Below is a sample record to discuss with your doctor.

Getting an A1C Test

Make sure to get an A1C test at least twice a year. Some people may need to have the test more often, so follow your doctor’s advice.

A1C results tell you your average blood sugar level over 3 months. A1C results may be different in people with hemoglobin problems such as sickle cell anemia. Work with your doctor to decide the best A1C goal for you. Follow your doctor’s advice and recommendations.

Your A1C result will be reported in two ways:

• A1C as a percentage.
• Estimated average glucose (eAG), in the same kind of numbers as your day-to-day blood sugar readings.

If after taking this test your results are too high or too low, your diabetes care plan may need to be adjusted. Below are ADA’s standard target ranges:

Questions To Ask Your Doctor

When visiting your doctor, you might keep these questions in mind to ask during your appointment.

• What is my target blood sugar range?
• How often should I check my blood sugar?
• What do these numbers mean?
• Are there patterns that show I need to change my diabetes treatment?
• What changes need to be made to my diabetes care plan?

If you have other questions about your numbers or your ability to manage your diabetes, make sure to work closely with your doctor or health care team.

Why do I need to know my blood sugar numbers?

Your blood sugar numbers show how well your diabetes is managed. And managing your diabetes means that you have less chance of having serious health problems, such as kidney disease and vision loss.

As you check your blood sugar, you can see what makes your numbers go up and down. For example, you may see that when you are stressed or eat certain foods, your numbers go up. And, you may see that when you take your medicine and are active, your numbers go down. This information lets you know what is working for you and what needs to change.

How is blood sugar measured?

There are two ways to measure blood sugar.

• Blood sugar checks that you do yourself. These tell you what your blood sugar level is at the time you test.
• The A1C (A-one-C) is a test done in a lab or at your provider’s office. This test tells you your average blood sugar level over the past 2 to 3 months.

How do I check my blood sugar?

You use a blood glucose meter to check your blood sugar. This device uses a small drop of blood from your finger to measure your blood sugar level. You can get the meter and supplies in a drug store or by mail.

Read the directions that come with your meter to learn how to check your blood sugar. Your health care team also can show you how to use your meter. Write the date, time, and result of the test in your blood sugar record. Take your blood sugar record and meter to each visit and talk about your results with your health care team.

What are target blood sugar levels for people with diabetes?

A target is something that you aim for or try to reach. Your health care team may also use the term goal. People with diabetes have blood sugar targets that they try to reach at different times of the day. These targets are:

• Right before your meal: 80 to 130
• Two hours after the start of the meal: Below 180

Talk with your health care team about what blood sugar numbers are right for you.

How often should I check my blood sugar?

The number of times that you check your blood sugar will depend on the type of diabetes that you have and the type of medicine you take to treat your diabetes. For example, people who take insulin may need to check more often than people who do not take insulin. Talk with your health care team about how often to check your blood sugar.

The common times for checking your blood sugar are when you first wake up (fasting), before a meal, 2 hours after a meal, and at bedtime. Talk with your health care team about what times are best for you to check your blood sugar.

What should I do if my blood sugar gets too high?

High blood sugar is also called hyperglycemia (pronounced hye-per-gly-see-mee-uh). It means that your blood sugar level is higher than your target level or over 180. Having high blood sugar levels over time can lead to long-term, serious health problems.

If you feel very tired, thirsty, have blurry vision, or need to pee more often, your blood sugar may be high.

Check your blood sugar and see if it is above your target level or over 180. If it is too high, one way to lower it is to drink a large glass of water and exercise by taking a brisk walk. Call your health care team if your blood sugar is high more than 3 times in 2 weeks and you don’t know why.

What should I do if my blood sugar gets too low?

Low blood sugar is also called hypoglycemia (pronounced hye-poh-gly-see-mee-uh). It means your blood sugar level drops below 70. Having low blood sugar is dangerous and needs to be treated right away. Anyone with diabetes can have low blood sugar. You have a greater chance of having low blood sugar if you take insulin or certain pills for diabetes.

Carry supplies for treating low blood sugar with you. If you feel shaky, sweaty, or very hungry, check your blood sugar. Even if you feel none of these things, but think you may have low blood sugar, check it.

If your meter shows that your blood sugar is lower than 70, do one of the following things right away:

• chew 4 glucose tablets
• drink 4 ounces of fruit juice
• drink 4 ounces of regular soda, not diet soda or
• chew 4 pieces of hard candy

After taking one of these treatments, wait for 15 minutes, then check your blood sugar again. Repeat these steps until your blood sugar is 70 or above. After your blood sugar gets back up to 70 or more, eat a snack if your next meal is 1 hour or more away.

If you often have low blood sugar, check your blood sugar before driving and treat it if it is low.

What do I need to know about the A1C test?

The A1C test tells you and your health care team your average blood sugar level over the past 2 to 3 months. It also helps you and your team decide the type and amount of diabetes medicine you need.

What is a good A1C goal for me?

For many people with diabetes, the A1C goal is below 7. This number is different from the blood sugar numbers that you check each day. You and your health care team will decide on an A1C goal that is right for you.

How often do I need an A1C test?

You need to get an A1C test at least 2 times a year. You need it more often if:

• your number is higher than your goal number
• your diabetes treatment changes

How do I pay for these tests and supplies?

Medicare, Medicaid and most private insurance plans pay for the A1C test and some of the cost of supplies for checking your blood sugar. Check your plan or ask your health care team for help finding low cost or free supplies. Ask your health care team what to do if you run out of test strips.

What if I have trouble getting to my blood sugar goals?

There may be times when you have trouble reaching your blood sugar goals. This does not mean that you have failed. It means that you and your health care team should see if changes are needed. Call your health care team if your blood sugar is often too high or too low. Taking action will help you be healthy today and in the future.

John's Story

At each visit, John and his health care team look at his A1C test results, his blood glucose meter and his blood sugar record to see if his treatment is working. At today’s visit, John’s A1C and blood sugar numbers are too high. John and his health care team talk about what he can do to get closer to his A1C and blood sugar goals. John decides he will be more active. He will:

• increase his walking time to 30 minutes every day after dinner.
• check his fasting blood sugar in the morning to see if being more active improves his blood sugar.
• call his doctor in 1 month for a change in medicine if his blood sugar levels are still too high.
• have his A1C tested again in 3 months to see if his new plan is working.

Things to remember

• Check your blood sugar as many times a day as your health care team suggests.
• Have your A1C checked at least 2 times a year.
• Keep a record of your blood sugar and A1C numbers.
• Take your blood glucose meter and blood sugar record to your visit and show them to your health care team. Tell your health care team how you think you are doing.
• Call your health care team if your blood sugar is often too high or too low.

Work with your health care team and decide what changes you need to make to reach your blood sugar goals.

Glucose meters test and record how much sugar (called glucose) is in your blood. They help you track your blood sugar level at different times of the day and night.

Meters can help you know how well your diabetes medicines are working. They can also help teach you how the food you eat and exercise can change your blood sugar level.

Three things you will need with your meter:

• Lancet - A small needle used to get a drop of blood from your finger or other part of your body.
• Test Strip - The strip goes into the meter. You put a drop of blood on the strip.
• Control Solution - Liquid used to make sure your meter is working right.

Meters come in different sizes. Meters also come with different features. Some meters let you track and print out your test results. Others have audio and larger screens to help people who have problems seeing. The meter you choose should fit your lifestyle and your needs.

7 Helpful Tips for Testing Your Blood Sugar and Caring for Your Meter

• Read the directions for your meter and test strips before you use them.

• Wash your hands before you check your blood sugar. Food or juice on your fingers could make the meter give you the wrong  result.

• Use the right test strip for your meter. The meter may not work right or may give you the wrong result if you use the wrong test strip.

• Write down your results and the date and time you tested. Do this even if your meter tracks your numbers. Take the results with you when you go to your doctor.

• Clean your meter as directed. Some cleaning products may harm your meter.

• Ask your healthcare provider if your medicines will change your blood sugar. If you are a kidney patient on dialysis, the dialysis solution can change your blood sugar.

• Take your meter with you when you go to your doctor. This way you can test your blood sugar in front of the doctor or nurse to make sure you are doing it the right way. Your health care provider may be able to print out your blood sugar results from your meter.

Testing Your Blood Glucose Accurately

It is important to test your blood glucose (sugar) accurately so you can manage your blood glucose levels. Keeping your blood glucose under control helps you feel better and lowers the risk of blindness, kidney disease, and nerve damage.

Tips for Using Your Blood Glucose Meter

Although blood glucose meters are simple to operate, many things can go wrong. Follow the tips below to get the most accurate results from your blood glucose meter.

Preparing to Test

Read and save all instructions for your meter and test strips.

Watch and practice with an experienced blood glucose meter user, a diabetes educator, or a healthcare professional. Don't be afraid to ask questions!

Wash your hands. Even small amounts of food or sugar on your fingers can affect your results.

Read the test strip packaging to make sure the strips will work with your meter.

Do not use test strips from a cracked or damaged bottle.

Do not use test strips that have passed their expiration dates.

Make sure you have entered the correct calibration code (if your meter requires one).

Test strips may look alike, but they are not all the same. Strips often have very specific chemical coatings or sizes. Even if an incorrect test strip fits in your meter, it could

Testing Your Blood Glucose

Use the correct blood drop size. If there is not enough blood on the test strip, the meter may not read the blood glucose level accurately. Repeat the test if you have any doubts.

Let the blood flow freely from your fingertip; do not squeeze your finger. Squeezing your finger can affect the results.

Use a whole test strip each time you use your meter.

Insert the test strip into the meter until you feel it stop against the end of the meter guide.

Even if your meter is supposed to give an error message when the blood drop is too small, the message may appear only when the drop is much too small. If the blood drop is too small, your meter can be wrong without giving an error message!

Maintaining Your Blood Glucose Meter

• Keep your meter clean.
• Test your meter regularly with control solution.
• Keep extra batteries charged and ready.
• Store your meter and supplies properly. Heat and humidity can damage test strips.
• Replace the bottle cap promptly after removing a test strip.

Following Up

Take your meter with you when you visit your doctor so you can compare it with your laboratory results.

Talk with your doctor or call the manufacturer's toll-free phone number if you are having problems with your meter.

Note on Alternative Site Testing:

Some blood glucose meters can use blood samples from the upper arm, forearm, base of the thumb, or thigh.

Using alternative sites gives you more options. But be aware that blood glucose levels from these sites may not always be as accurate as readings from the fingertips. Alternative site results differ from fingertip results when glucose levels are changing rapidly such as after a meal, after taking insulin, during exercise, or when you are ill or under stress.

Use blood from a fingertip rather than an alternative site if:

• you think your blood glucose is low,
• you don't regularly have symptoms when your blood glucose is low, or
• how you feel doesn’t match the results from the alternative site.

Caution: Not all meters can use blood from alternative sites, and not all alternative sites are the same. Only test from sites that are identified in the instructions. Alternative site testing is not for everyone. Talk with your doctor before you test from a site other than your fingertip.

Recognizing Low and High Blood Glucose

Some people have recognizable symptoms of low or high blood glucose and some do not. The only reliable way to know when you have low or high blood glucose is to test it.

When your blood glucose is low, you may feel faint, shaky, dizzy, or confused. You may begin to sweat. You may have a headache, sudden behavior change, or seizure.

When your blood glucose is high, your symptoms may be similar to when your blood glucose is low. You may feel dizzy or have a headache. You may also feel thirsty or have an urgent need to urinate.

But many people have no symptoms with low or high blood sugar levels. Other people have symptoms that change over time, so they no longer recognize them. Often, older patients or people who have had diabetes for many years stop having symptoms.

Blood Glucose Meters Are Not Perfect

Although blood glucose meters are generally reliable and help to manage diabetes, they are not perfect. The technology used in blood glucose meters is not as accurate as testing done in a hospital or a doctor’s office.

Your blood glucose meter may give a wrong reading if you are dehydrated, are going into shock, or have a high red blood cell count (hematocrit). Even a very low blood glucose level can cause an incorrect reading.

If you suspect your blood glucose is too low or too high, call your doctor or go to an emergency room immediately… even if your meter shows that everything is fine.

Reporting Problems With Your Glucose Meter

FDA encourages you to report any serious injuries, deaths or malfunctions you experience with medical products. FDA will take action when needed to protect the public’s health.

Report the events to FDA at 1-800-332-1088 and to the product manufacturer.

Using a glucose meter to check and monitor blood sugar is a daily part of life for millions of Americans with diabetes.

Glucose meters and test strips are medical devices regulated by the U.S. Food and Drug Administration. And the FDA wants to make sure you use these devices safely. Read on for advice.

Beware of Buying Previously Owned Test Strips

Test strips are part of many tests for home use that allow people to test for or monitor some diseases or health conditions, including diabetes. The FDA is aware that some sellers are marketing pre-owned or secondhand test strips to consumers. These are unused test strips previously owned by someone else.

These pre-owned strips may be sold at lower prices when compared to new strips. For instance, you may see flyers advertising cheap test strips in your neighborhood, or you may see sellers marketing cheap test strips online. But pre-owned strips can give incorrect results and may not be safe for use with devices.

Here’s more information to consider.

• Test strips should be properly stored to give accurate results. If you buy pre-owned strips, it is hard to know whether the strips were stored properly. Test strips also could be expired. A lack of proper storage or using expired strips could put you at risk for getting incorrect results from your glucose meter. And incorrect results can put you at risk for serious health complications — and even death.
• Test strip vials that have been opened by another person may have small amounts of blood on them, which can put you at risk for infection.
• Pre-owned test strip vials may have been tampered with, which means that they may not be safe to use. For instance, the expiration dates might have been changed or covered up.
• Pre-owned strips also may not have been cleared by the FDA for sale in the United States. If instructions aren’t in English or the strips look different than other strips of the same brand, this can be a sign of unsafe strips.

The bottom line? When it comes to buying test strips—including glucose test strips designed for your meter—the FDA recommends that you buy new, unopened vials and that you do not buy pre-owned test strips.

Talk to your health care provider if you are not sure where to buy test strips for your glucose meter or if you cannot afford to buy the test strips recommended for use with your meter.

7 More Safety Considerations for Glucose Meters and Test Strips

You may be a pro at testing your blood sugar levels. But consider these safety reminders.

Follow instructions carefully. Glucose meters and test strips are sold with instructions for use. You can call the manufacturer of your device or your health care provider if you have questions.

Ask your health care provider to watch you test yourself. He or she can tell you if you are using your device correctly.

Do quality control checks of your device. Regularly test your meter using a control solution to make sure the test strips and meter are working properly together. Read the meter’s instructions for use to see how often you should test it.

Understand what the meter display means. Be sure you know how high and low glucose values are displayed on your meter. Sometimes they are displayed as “LO” or “HI” when the glucose level is beyond the range than the meter can measure. Talk to your health care provider if you have questions.

Know which test site gives the most accurate results. Readings from other areas of your body may not be as correct as fingertip readings.

• Readings from alternate sites—such as your forearm or palm—can be less accurate than fingertip readings when your glucose levels change quickly, for example, after you eat or during exercise.
• Take a reading from a fingertip if you think your blood glucose is low, if you don't normally have symptoms when your blood glucose is low, or if results from an alternate test site don’t match how you feel.

Know when and how to clean and disinfect your glucose meter. Cleaning and disinfection instructions can vary, so always read and follow the directions in your manual.

Know when to report device problems. In an emergency, call 9-1-1. For non-emergencies, the FDA encourages you to report any issues to MedWatch, the FDA’s voluntary reporting program. (Problems may include devices that don’t work, suspected incorrect results, or any other problem with your meter or test strips.)

This section will provide you with information on how to report problems you may encounter when using your glucose meter or your continuous glucose monitoring system (CGMS).

If you would like to notify the FDA directly about a problem with a glucose meter or a CGMS, contact us using the information at the bottom of this page. In your e-mail, please include as much of the following information as possible:

• brand of the meter or GGMS involved (and the model or catalog number, if known)
• lot number of the test strip or sensor involved
• date of the event
• whether you are the patient or family member or a health care provider
• whether or not the manufacturer was notified about the problem
• the patient's age
• description of patient’s symptoms at the time of the event
• description of the event, such as:
  • initial meter or CGMS test result
  • If the test was repeated, provide the test result(s) and indicate how long after the initial test the repeat testing was performed (e.g., 10 minutes later).
  • Indicate whether the same testing device was used for repeat testing or if a different glucose testing device was used. If different, provide any information that is known about the 2nd testing device. Be sure to specify if any of testing was performed by a health care facility.

Once a glucose meter or a CGMS goes into widespread use, unforeseen problems may arise because the FDA's clearance and approval processes cannot always detect adverse events that are rare or related to the clinical use of the device or the users’ techniques and skills. The FDA also cannot always detect manufacturing problems or problems with the product labeling (including instructions for use) until after the device is on the market.

To identify these problems, the FDA and manufacturers depend on reports from the individuals who use glucose meters or CGMSs.

What types of problems should be reported?

Device problems including:

• reagent or instrument failure/defective devices
• defects in product design
• product instability
• any other device problems that compromise patient health or safety
• failure to perform according to performance characterized in package insert
• incorrect test results (falsely elevated or decreased glucose results) that cause or contributed to an incorrect patient diagnosis and/or treatment
• unexplained quality control (QC) failures, contamination or stability problems with the quality control solutions or test strips
• "near misses" where under slightly different circumstances, a serious injury or death might have occurred, or use error

Use-related problems including:

• inadequate and/or misleading labeling or confusing user instructions
• product confusion caused by name, labeling, design, or packaging
• inadequate packaging or poor package design
• any other user problems that compromise patient health or safety

Who should report problems with glucose meters and CGMSs?

• User facilities, including hospitals, ambulatory surgical facilities, nursing homes, outpatient treatment facilities, or outpatient diagnostic facilities are required to report:
  • device-related events that have caused, or may have caused or contributed to a death to both the FDA and the manufacturer
  • device-related events that have caused, or may have caused or contributed to a serious illness or injury to the manufacturer. If the medical device manufacturer is unknown, the serious injury is reported by the facility to the FDA.
• All other glucose meter and CGMS users, including doctors and patients, are encouraged to voluntarily report device problems directly to the manufacturer and/or the FDA whenever it is suspected that the product caused or contributed to an adverse outcome.

What happens to your report?

When the FDA receives a report from a user facility, device user or an individual health care provider, it is entered in the medical device postmarket surveillance database. The FDA continually reviews the database to detect problems, trends, and potential hazards. When the FDA detects risks or potential risks associated with the use of a particular product, the agency can take corrective actions and notify the public.

Who has access to your report?

The FDA is aware that glucose meter and CGMS users are concerned about the issue of confidentiality and public availability of reports. For all reports, the FDA holds the patient's identity in strict confidence and protects it to the fullest extent of the law. The FDA will not release any patient identifiers to the public. Reporters can assist in this process by not using the patient's name, initials, or other identifying information. The reporter's identity, including the identity of a self-reporter, may be shared with the manufacturer unless requested otherwise (there is a check-off box on the report form). However, the FDA will not disclose the reporter's identity in response to a request from the public, pursuant to the Freedom of Information Act.

How do you Report a Problem?

Problems can be reported through the MedWatch Online Voluntary Reporting Form

Blood sugar levels change often during the day. When they drop below 70 mg/dL, this is called having low blood sugar. At this level, you need to take action to bring it back up. Low blood sugar is especially common in people with type 1 diabetes.

Knowing how to identify low blood sugar is important because it can be dangerous if left untreated. Read more about what causes low blood sugar and common symptoms.

Causes of Low Blood Sugar

There are many reasons why you may have low blood sugar, including:

• Taking too much insulin.
• Not eating enough carbs for how much insulin you take.
• Timing of when you take your insulin.
• The amount and timing of physical activity.
• Drinking alcohol.
• How much fat, protein, and fiber are in your meal.
• Hot and humid weather.
• Unexpected changes in your schedule.
• Spending time at a high altitude.
• Going through puberty.
• Menstruation.

Symptoms of Low Blood Sugar

How you react to low blood sugar may not be the same as how someone else with low blood sugar reacts. It’s important to know your signs. Common symptoms may include:

• Fast heartbeat
• Shaking
• Sweating
• Nervousness or anxiety
• Irritability or confusion
• Dizziness
• Hunger

Hypoglycemia Unawareness

If you’ve had low blood sugar without feeling or noticing symptoms (hypoglycemia unawareness), you may need to check your blood sugar more often to see if it’s low and treat it. Driving with low blood sugar can be dangerous, so be sure to check your blood sugar before you get behind the wheel.

You may not have any symptoms when your blood sugar is low (hypoglycemia unawareness). If you don’t have symptoms, it will be harder to treat your low blood sugar early. This increases your risk of having severe lows and can be dangerous. This is more likely to happen if you:

• Have had diabetes for more than 5-10 years.
• Frequently have low blood sugar.
• Take certain medicines, such as beta blockers for high blood pressure.

If you meet one or more of the above and you have hypoglycemia unawareness, you may need to check your blood sugar more often to see if it’s low. This is very important to do before driving or being physically active.

Types of Low Blood Sugar

Nighttime low blood sugar

While low blood sugar can happen at any time during the day, some people may experience low blood sugar while they sleep. Reasons this may happen include:

• Having an active day.
• Being physically active close to bedtime.
• Taking too much insulin.
• Drinking alcohol at night.

Eating regular meals and not skipping them can help you avoid nighttime low blood sugar. Eating when you drink alcohol can also help. If you think you’re at risk for low blood sugar overnight, have a snack before bed.

You may wake up when you have low blood sugar, but you shouldn’t rely on that. A continuous glucose monitor (CGM) can alert you with an alarm if your blood sugar gets low while you’re sleeping.

Severe low blood sugar

As your low blood sugar gets worse, you may experience more serious symptoms, including:

• Feeling weak.
• Having difficulty walking or seeing clearly.
• Acting strange or feeling confused.
• Having seizures.

Severe low blood sugar is below 54 mg/dL. Blood sugar this low may make you faint (pass out). Often, you’ll need someone to help you treat severe low blood sugar.

People with diabetes may experience low blood sugar as often as once or twice a week, even when managing their blood sugar closely. Knowing how to identify and treat it is important for your health.