Blood glucose monitoring is the regular testing of the level of sugar (glucose) in your blood. It is part of the ongoing care for diabetes.
Glucose testing can be done using a portable blood glucose monitor called a glucometer. The test involves pricking your finger to obtain a small blood sample for the glucometer to analyze.
Blood glucose monitoring kits and supplies are available for purchase at pharmacies and online. Glucose meters come with testing strips, small needles to prick your fingers, and a logbook to record your blood sugar numbers over time.
Blood glucose monitoring can help manage diabetes and, ultimately, control many of the symptoms of diabetes. It can alert you when it is time for an insulin shot to lower your blood glucose level or when you need to eat in order to raise it.
Your doctor will calculate the target range for your blood glucose based on your age, type of diabetes, overall health, and other factors. It is important to keep your glucose levels within your target range because high blood sugar levels, if untreated, can severely damage your arteries, cause nerve damage and kidney failure. Low blood sugar levels, on the other hand, can cause a variety of symptoms from mild to moderate confusion and weakness to serious disorders such as coma.
Regular glucose monitoring can help people with diabetes learn more about their condition and how their blood glucose levels are affected by activities and conditions, including:
Blood glucose monitoring can also help to alert you if your blood glucose levels become dangerously high or low.
There is a small risk of infection at the site where you prick your finger to retrieve a blood sample. There is also a risk of spreading blood-borne illness if you share insulin needles and testing supplies with someone else. You should never share needles or finger-stick devices with anyone for any reason.
Risks from the blood glucose test, which are minimal, are substantially lower than the risk of not monitoring your blood sugar levels.
Before checking your blood glucose levels, make sure that you have all the necessary equipment:
- finger-stick device to prick your finger
- alcohol swab to sterilize the puncture site
- blood glucose monitor
Also, depending on the type of test you are taking — while fasting or before or after meals — you may need to adjust your eating schedule.
Before you begin, wash your hands thoroughly to prevent infection at the finger-prick site.
You will then prick your finger or another area of your body to draw a small amount of blood. You will apply the blood to a special test strip and insert the strip into the glucometer. Your monitor will give you your blood glucose reading on its digital display.
Finger pricks rarely require a bandage, but you may want to use one if bleeding continues beyond a few drops. It’s important to follow all the instructions that came with your glucometer to ensure accurate results.
According to the Mayo Clinic, normal results for blood glucose testing fall into the follow ranges:
- Before meals: 70 to 130 mg/dL
- One to two hours after meals: lower than 180 mg/dL
- After fasting for eight hours or more: 90 to 130 mg/dL
Low blood glucose levels indicate hypoglycemia, which can usually be corrected by eating something or adjusting your next dose of insulin.
High blood glucose levels indicate hyperglycemia, which may require an insulin shot or fasting.
Regular blood glucose monitoring can help you identify fluctuations in your blood sugar levels so you can learn how food, exercise, stress, and other factors affect your diabetes.