Blood Sugar Monitoring: Why, How & When To Check (2024)

Why should I monitor my blood sugar?

If you have diabetes, monitoring your blood sugar (glucose) is key to finding out how well your current treatment plan is working. It gives you information on how to manage your diabetes on a daily — and sometimes even hourly — basis.

Monitoring your blood sugar is important when you have diabetes, especially if you use insulin. The results of blood sugar monitoring can help you make decisions about food, physical activity and dosing insulin.

Several things can affect your blood sugar. You can learn to predict some of these impacts with time and practice, while others are very difficult or impossible to predict. That’s why it’s important to check your blood sugar regularly if your healthcare provider recommends doing so.

For example, the following situations typically raise blood sugar levels:

• Consuming carbohydrates.
• Not taking enough diabetes medication or insulin or missing a dose.
• Consistent lack of exercise or getting less activity than you usually do.
• Taking corticosteroid (steroid) medications.
• Illness, surgery or stress.
• Dawn phenomenon (an early-morning rise in blood sugar that’s likely due to natural fluctuations in hormones, such as cortisol).
• Smoking.
• Dehydration.
• Puberty.

The following situations typically lower your blood sugar:

• Missing meals.
• Taking too much diabetes medication or insulin.
• Physical activity.

The following situations can raise and/or lower your blood sugar depending on other factors and your unique biology:

• Periods (menstruation).
• Food and medication/insulin timing.
• Drinking beverages containing alcohol.
• Non-diabetes medication interactions.

Due to all of these varying factors, it’s essential to monitor your blood sugar if you have diabetes. It’s the only way to know for sure when your blood sugar levels are changing. And it helps you and your healthcare provider know how to adjust your management.

How can I monitor my blood sugar at home?

There are two main ways you can monitor your blood sugar at home if you have diabetes:

• With a glucose meter and finger stick.
• With a continuous glucose monitor (CGM).

You may choose either or both methods for a variety of reasons, such as:

• Your access to the technology, which can vary due to cost and medical insurance coverage.
• What form of diabetes you have.
• How often your healthcare provider recommends checking your blood sugar.
• Your overall health.

Glucose meters and test strips

The most common type of blood sugar monitoring involves using a glucose meter and test strips. This is a “finger stick check.” You prick your fingertip with a small needle called a lancet to produce a blood drop. You then place the drop against the test strip in the glucose meter, and the meter shows your blood sugar level within seconds.

Finger stick checks only measure blood glucose at one moment in time, so people with diabetes, especially those taking insulin, often have to check their blood sugar several times a day using this method.

Glucose meters and test strips are available at your local pharmacy, through mail order or through your healthcare provider. There are many different types of glucose meters. Your healthcare provider can help you select the meter that’s best for you.

If you have medical insurance, check with your insurance company to see if they cover glucose meters and test strips. Some insurances only cover certain brands. If you don’t have insurance, check with your provider for other options.

CGMs

CGM involves wearing a device that measures your glucose levels 24 hours a day. The device uses this data to form a graph that shows a more complete picture of how your blood sugar levels change over time.

Most CGM devices use a tiny sensor that you insert under your skin. The sensor measures glucose levels in the fluids between your body’s cells (interstitial fluid).

There are a few different types and brands of CGMs. Some CGMs link to specific insulin pumps. Others operate independently. Most CGMs can send alarms or alert messages when they detect low or high glucose levels.

Like all technology, CGMs can sometimes fail or be inaccurate. So, don’t completely rely on CGMs without finger stick checks, especially if your CGM readings don’t match the symptoms of low or high blood sugar you’re experiencing, or if your CGM gives you an error message.

Ask your healthcare provider about CGM options if you’re interested in using this technology. You’ll also need to check with your insurance company to see if they cover the costs and which brands they cover.

Tracking blood sugar levels

Most glucose meters allow you to save the results. You may be able to use an app on your smartphone to track your levels. If you don’t have a smartphone, keep a written record of your blood sugar levels that includes the date, time of the test and any other details, like if it was before or after a meal. You should bring your glucose meter, phone or written record with you each time you visit your healthcare provider.

CGM systems save the data of your glucose levels. Your provider will be able to access the information.