Blood Sugar Testing

About Blood Sugar Testing

The whole point of testing is to see how well you are doing on controlling your sugars. Being diabetic means that your body has lost the ability to control its blood sugar level. To remain healthy, it is a good idea to try to keep your blood sugar as close to normal as possible. There are three times that you need to be concerned about your blood sugar reading

when you wake (your fasting number)
around meals
before you go to sleep

What units am I testing in?

The USA uses mg/dl. Most of the rest of the world uses mmol. To go from mmol to mg/dl, multiply by 18. To go the other way, divide by 18.

3.9 mmol X 18 = 70 mg/dl
5.0 mmol X 18 = 90 mg/dl
5.5 mmol X 18 = 100 mg/dl
8.0 mmol X 18 = 144 mg/dl

When you are testing, make sure your meter is set to the proper unit.

When you wake

Thus number can tell you about your overall diabetes condition. The ADA says that a normal fasting number is below 100 mg/dl. For me, this number is affected mostly by what I did the day before, whether or not I exercised, and how my diet was.

Around meals

There are three reasons to test before a meal.

if you take insulin, you need to know where you start in order to calculate your insulin dose
to see how much you can eat this meal and have any hope of remaining within your high target number
to allow you to see just how high this meal spiked you

The reason to test after a meal is to see what this meal did to you. You want to keep any rise, or spike, from the meal as small as possible. I shoot for a max rise of 40 points.

You want to measure the highest point of the peak, which for most people is around the one hour point, and two hours after the meal, because by then any rise from the meal should be over.

Before you go to sleep

This gives you a measure of how well the day went from a blood sugar perspective. Plus, the difference between the bedtime number and the waking number gives you an idea of what happened during the night.

How does my daily number compare to my A1c?

Check out my page on the A1c test for that answer.