How often you use your meter each day depends on the type of diabetes you have and your individual treatment plan. If you have Type 1 diabetes, the ADA recommends checking your blood glucose at least three times daily and more often when there are any changes in your routine. If you have Type 2 diabetes and take insulin, the ADA suggests that you check your blood glucose at least three times daily as well.
There are no official recommendations for people with Type 2 diabetes who do not use insulin. However, even when you don’t use insulin, monitoring can help show you the effects of your food choices, physical activity, medicines, and stress-management efforts. Monitoring at different times on different days (as opposed to monitoring at the same times every day) gives you valuable information about your blood glucose level over the course of the day. (See “Twice-a-Day Monitoring Schedule” for a suggested schedule.) It allows you to see patterns in your blood glucose levels, such as highs or lows at particular times of day. Sharing this information with your health-care provider can help him make the best recommendations for fine-tuning your treatment.
When you check your blood glucose level, keep in mind that you are shooting for a range of blood glucose levels, not an exact number. If your blood glucose readings before lunch are 87 mg/dl, 97 mg/dl, 109 mg/dl, and 101 mg/dl for four consecutive days, they may appear to be fluctuating, but all of these levels are within the ADA and ACE target ranges, so they would not call for an adjustment in treatment.
The target ranges in the ADA and ACE guidelines are for blood glucose levels just before meals and two hours after the start of meals, and these are the times of day when many people routinely monitor. Many people also monitor at bedtime to determine whether a snack may be necessary to prevent hypoglycemia overnight. People who use insulin are advised to monitor before driving so that they catch — and treat — low blood glucose early and not develop hypoglycemia while driving. Other times to monitor are when you feel any symptoms of hypoglycemia (such as feeling tired, hungry, sweaty, shaky, dizzy, grouchy, or confused) or when you simply don’t feel well. Not every ill feeling is a result of having a high or low blood glucose level, but it’s better to check so that if high or low blood glucose is the problem, you can take steps to correct it.
No matter what your usual monitoring schedule, here are some reasons to check your blood glucose more frequently, at least temporarily:
- You are ill. (Even if you cannot eat, your blood glucose may be high because of the stress of the illness.)
- You have recently changed diabetes medicines.
- You have recently changed your meal plan.
- You have recently changed your level of physical activity or are trying a new type of sport or exercise.
- You are experiencing increased amounts of stress in your life.
- You are at a stage in your menstrual cycle when you usually experience rising or falling blood glucose levels.
Troubleshooting meter problems
When used correctly, your blood glucose meter should provide accurate readings. If you think something’s not right with your blood glucose monitoring results, start with the basics:
- Did you calibrate the meter for the test strip you used? Some newer meters don’t need to be calibrated, or coded, but others won’t give an accurate reading unless you enter the code number on the box or vial of test strips into the meter.
- Did you apply enough blood to the test strip? A too-small blood sample will yield an inaccurate reading.
- Was the finger that you pricked clean?
- Are your test strips expired?
- Have your test strips been stored properly? Strips that have been exposed to very high temperatures may give inaccurate results.
- Is the meter at room temperature? Your blood glucose meter may not work accurately at cold or very hot temperatures.
- Does the meter need new batteries? (Check the display screen.)
- Has the meter been dropped or damaged?