Blood glucose (blood sugar) monitoring is the primary tool you have to find out if your blood glucose levels are within your target range. This tells you your blood glucose level at any one time.
It’s important for blood glucose levels to stay in a healthy range. If glucose levels get too low, we can lose the ability to think and function normally. If they get too high and stay high, it can cause damage or complications to the body over the course of many years.
The logging of your results is vital. When you bring your log to your health care provider, you’ll have a good picture of your body's response to your diabetes care plan. To help keep track of your levels, we have a printable blood glucose log. We also have a blood glucose log available for purchase that is smaller so you can carry it with you.
Who should check?
Talk to your doctor about whether you should be checking your blood glucose. People who may benefit from checking blood glucose regularly include those:
- taking insulin.
- who are pregnant.
- having a hard time reaching your blood glucose targets.
- having low blood glucose levels.
- having low blood glucose levels without the usual warning signs.
- have ketones from high blood glucose levels.
How do I check?
People with diabetes check their blood glucose levels by poking their fingertips and using a blood glucose meter or a continuous glucose monitor (CGM) to measure the blood glucose level at that moment. Read on to find out how to use a blood glucose meter. To find out more about CGMs, start by talking to your doctor.
How to use a blood glucose meter:
- After washing your hands, insert a test strip into your meter.
- Use your lancing device on the side of your fingertip to get a drop of blood.
- Touch and hold the edge of the test strip to the drop of blood and wait for the result.
- Your blood glucose level will appear on the meter's display.
Note: All meters are slightly different, so always refer to your user's manual for specific instructions.
Other tips for checking:
- With some meters, you can also use your forearm, thigh, or fleshy part of your hand.
- There are spring-loaded lancing devices that make sticking yourself less painful.
- If you use your fingertip, stick the side of your fingertip by your fingernail to avoid having sore spots on the frequently used part of your finger.
What are the target ranges?
Blood glucose targets are individualized based on:
- duration of diabetes
- age/life expectancy
- conditions a person may have
- cardiovascular disease or diabetes complications
- hypoglycemia unawareness
- individual patient considerations
The American Diabetes Association suggests the following targets for most nonpregnant adults with diabetes. A1C targets differ based on age and health. Also, more or less stringent glycemic goals may be appropriate for each individual.
- A1C: Less than 7%
A1C may also be reported as eAG: Less than 154 mg/dL
- Before a meal (preprandial plasma glucose): 80–130 mg/dL
- 1-2 hours after beginning of the meal (postprandial plasma glucose)*: Less than 180 mg/dL
What do my results mean?
When you finish the blood glucose check, write down your results and note what factors may have affected them, such as food, activity, and stress. Take a close look at your blood glucose record to see if your level is too high or too low several days in a row at about the same time. If the same thing keeps happening, it might be time to change your diabetes care plan. Work with your doctor or diabetes educator to learn what your results mean for you. It can take time to make adjustments and get things just right. And do ask your doctor if you should report results out of a certain range right away by phone.
Keep in mind that blood glucose results often trigger strong feelings. Blood glucose numbers can leave you upset, confused, frustrated, angry, or down. It's easy to use the numbers to judge yourself. Remind yourself that tracking your blood glucose level is simply a way to know how well your diabetes care plan is working, and whether that plan may need to change.
What about urine checks for glucose?
Checking urine for ketones is important when your blood glucose levels are high or when you are sick. Talk to your doctor to find out if or when you should check for ketones.