How often should I check my blood glucose levels?

How often you monitor your blood glucose is highly individualized. It depends on:

• Whether you have type 1 or type 2 diabetes
• Your blood glucose goals
• How often you’re willing to prick your finger,
• What supplies you can afford 

How often you monitor also depends on your reasons for checking your blood glucose. The standard times to check your blood glucose if you have diabetes and are looking for patterns in blood glucose behavior are:

•  before breakfast, lunch, and dinner (or an especially big snack)
•  before you go to bed
•  1 to 2 hours after breakfast, lunch, and dinner (or an especially big snack)
•   at 2 or 3 a.m.

Well…. you’ve got ten fingers, right?

OK, relax. I was just teasing. The real answer is never less than two times. That’s because you need to test in pairs (thanks to diabetes educator William Polonsky for coining this term). One test tells you nothing because it has no context. Testing in pairs gives you context.

For example, if I told you that your blood sugar was 372mg/dL, would that be “bad?” Hmmm.... maybe, but not if it was 482 a while ago.

Ah ha. Now you are getting it.

Common pairs are before eating and two hours after eating. The numbers really don’t matter. It's the change in number that matters. If you only test after eating you might think the meal caused you to go too high. And it might have. Or you might have already been too high before the first bite. If you didn’t test, we’ll never know.

Another pair is between bedtime and first thing in the morning. This tells us if you are going up, down, or staying level during your sleep. Before and after exercise is another good pair.

Remember, the numbers themselves are meaningless. You need to look at the changes in numbers. If you are always high or low at the first check there is a problem that needs to be solved, but it has nothing to do with the specific pair.

So how many pairs should you do? As many as your insurance will pay for, of course. The more you test the more you know. The more you know the better you can control your diabetes. The better you control your diabetes the longer, and healthier, and happier your life will be. So if my math is right, the more you test, the happier you will be.

What if your insurance will only pay for one strip per day? Well, you either have to get your wallet out or you have to get creative. If your doc says it is safe for you to do so, test every-other-day, taking your once daily strip and still using it for pairs. If your strips are severely limited you can focus one week on a certain time of day and the next week on a different time or activity.