Are you testing more and understanding it less? The readings you get can be hard to understand- the numbers seem to go up and down for no apparent reason. But, it’s easier to test more often if you understand what the numbers are telling you and use that information.
The blood sugar test that you do at home tells you how much sugar (in milligrams or mg) is in a deciliter (1/10th of a liter or dL) of blood at that moment. Your blood sugar levels change based on:
- what, when and how much you eat
- exercise
- type, time and dose of insulin injections
- type, time and dose of diabetes pills you take
- your stress level
But how do you interpret the numbers? The American Diabetes Association recommends the following levels based on research about the effect of blood sugar on complications:
- Pre-meal blood 90-130 mg/dL plasma sugar
- Post-meal Less than 180 mg/dL plasma sugar
If these numbers seem higher than in the past, it is because they are based on plasma blood sugar readings. Blood glucose meters used to give the results for whole blood. Recently, meters have changed to provide plasma values, which are 10 to 15 percent higher. To find out which your meter reads, check the booklet that came with the meter or call the toll free number on the back.
These numbers can be a guide for choosing your own goals. Think about how hard you are willing and able to work and seek the advice of your health care team. Choose a range you can reach, where you feel well and that will help lower your risk for the complications of diabetes.
Think of your range as a target. You may not always hit your target, but it is where you are most of the time that matters. Choose a target range for both your fasting and after meal blood sugar levels.
Your fasting (or before breakfast) blood sugar sets the stage for the rest of the day. If your before breakfast blood sugar reading is high, its harder to bring it into range once you eat. Your before breakfast blood sugar is affected by your evening snack, your dose of bedtime insulin or diabetes pills, the sugar that your liver makes during the night, and hormones that cause your blood sugar to go up during the night. To lower your fasting blood sugar you can change your evening medicines (the type, dose or time you take them) or adjust your snack.
You can find out what happens to your blood sugar after you eat by testing one or two hours following a meal. This reading is affected by the type and amount of carbohydrate you ate, the timing and type of exercise before your meal, your medication and your stress level. To lower your after meal blood sugar, you can eat less carbohydrate or adjust your medicine.
Knowing your fasting blood sugar gives you part of the picture, but testing after you eat helps you to see the whole picture. A plan that many people use is to test their blood sugar before breakfast every day and then one other time at different times each day. For example, you might test before breakfast and lunch on Monday and before breakfast and after lunch on Tuesday.
If you see a number that is higher or lower than you expect, think about why. Did you eat less than usual? Did you eat at a different time? Did you get more exercise than usual? Did you take your diabetes pills or insulin at a different time than usual? Are you more stressed? The answer may not always be clear, but thinking about it can help.
Write down your blood sugar so you can look for patterns. Look at all of your readings at the same time of day for a week or two. Is your blood sugar usually in your target range, or too high or low most days at that time? On days when it was different from usual, can you think of a reason? If your blood sugar level is often out of your target range, your medicine, meal plan, activity or schedule may need adjusting.
Remember that your reading is simply a measure of the sugar in your blood. It is not a judgment about the kind of person you are or whether you are good or bad. Blood sugar tests give you the information you need to make choices and decisions about how you care of yourself and your diabetes. You are not testing for your doctor, spouse, children, educator or dietitian. It’s not worth all of the pain, cost and hassle unless you are doing it for yourself -to make decisions for today and your future health.
