If you are someone with diabetes, you have probably been told to check your blood sugar. But do you know what that means and why you should test?
Blood sugar, or glucose, is the primary type of sugar in the body. It comes from carbohydrates found in foods. Glucose is essential for providing energy to cells throughout the body. What you eat, physical activity, stress level and diabetes medications all affect your blood sugar. Knowing your blood sugar can help you adjust your eating habits and activity levels to better manage your diabetes. This information can also help your medical provider determine if they need to change or add diabetes medication.
Common questions for testing include:
- Do I need to test my blood sugar?
- How do I test my blood sugar?
- How often should I test?
- What do the numbers mean?
Let’s dive into each of these questions.
Do I need to test my blood sugar?
Knowing your blood sugar is important when taking diabetes medications that lower your blood sugar. Testing provides data to help guide your medication dosage. Some diabetes medications, such as insulin, require you to test your blood sugars because too much insulin increases your risk of having low blood sugar which can be a medical emergency. If you have diabetes and become pregnant or develop diabetes while pregnant, also known as gestational diabetes, it is recommended you test multiple times a day or use a Continuous Glucose Monitor (CGM). Keeping blood sugars in range during pregnancy lowers the risk of complications for both the mother and baby.
How do I test my blood sugar?
Blood sugar testing at home can be done with two devices: blood sugar meters (also known as glucometers) or a CGM. Blood sugar meters use a drop of blood to check your blood sugar.
A CGM is a wearable device that measures and tracks blood sugar levels 24-hours a day. CGMs measure blood sugar every one to five minutes and can be viewed either through a reader or by a linked cell phone. Additional CGM features may include the ability of your medical provider to view your blood sugar remotely or connecting with an insulin pump.
Both meters and CGMs give you information on your blood sugar levels. Meter and CGM costs vary by manufacturer and insurance coverage so check with your insurance to know which device is covered. If you aren’t sure which one is right for you, talk to your medical provider or a diabetes educator for more information.
How often should I test?
Testing recommendations vary based on the type of diabetes, the number of diabetes medications, and the type of medication. Your healthcare team can help you decide when to check your blood sugar levels. If you need assistance with learning how to use a blood sugar meter or CGM, ask for a referral to see the diabetes educator who can provide training.
In general, recommended times to test blood sugar include:
- When you first wake up (fasting)
- Before meals
- Two hours after the start of a meal
- At bedtime
What do the numbers mean?
You and your medical provider may decide on personalized blood sugar levels. However, the general range for blood sugar levels for adults, NOT pregnant, include:
- Fasting or before a meal: 80 – 130 mg/dL
- Two hours after a meal: Below 180 mg/dL
Blood sugars that are high (hyperglycemia) can cause low energy and damage to cells which can lead to long-term complications such as blindness, kidney failure and amputations. Symptoms of high blood sugar include blurry vision, thirst, urinating (peeing) often and weakness. If your blood sugar is high, drink water, limit sugars and starchy foods (e.g., bread, potatoes, rice, fruit, etc.) and do some light activity to help lower your blood sugar. Make sure you can safely do the activity before starting any exercise.
Blood sugars that are low (hypoglycemia) are usually lower than 70 mg/dL. Symptoms include hunger, confusion, dizziness, shakiness and/or a fast heartbeat. At times, you may experience these symptoms even if your blood sugar is above 70 mg/dL. Low blood sugar can be dangerous, so it is important to treat quickly. Treat low blood sugar with a small amount of sugar (15 grams) such as 4 ounces of juice, four glucose tablets, 1 tablespoon of sugar, honey, or corn syrup, or one dose of glucose gel. Recheck your blood sugar in 15 minutes and treat again if blood sugar is still low. Once your blood sugar is above 70 mg/dL, eat a balanced snack or meal with protein and carbs to help keep your blood sugar from going low again.
What does this mean for me?
If you have diabetes, the benefits of monitoring your blood sugar allow you to live well with diabetes. Everyone is different so knowing how your food, activity, medication and even stress impact your blood sugar is important. Knowledge is power so it’s important to know your numbers! If you have questions, talk to your medical provider or diabetes educator to personalize a monitoring plan that is right for you.
