"If you have diabetes, you'll likely need a blood glucose meter to measure and display the amount of sugar (glucose) in your blood. Exercise, food, medications, stress and other factors affect your blood glucose level. Using a blood glucose meter can help you better manage your diabetes by tracking any fluctuations in your blood glucose level."
https://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/blood-glucose-meter/art-20046335
"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."
https://www.cdc.gov/diabetes/managing/managing-blood-sugar/bloodglucosemonitoring.html
"Blood sugar monitoring is one of the most important aspects of managing diabetes, especially for people who have type 1 diabetes and those who take insulin. You can check your blood sugar by using a glucose meter and test strips or a CGM system. Your healthcare provider will help you determine how often and when you should check your blood sugar."
https://my.clevelandclinic.org/health/treatments/17956-blood-sugar-monitoring
Blood Glucose Monitoring
https://www.ncbi.nlm.nih.gov/books/NBK555976/