Smart Testing Can Help You Control Your Diabetes

Medically Reviewed by Michael Dansinger, MD on December 15, 2015
From the WebMD Archives

Testing your blood sugar is a basic part of life for most people with diabetes. The numbers tell you and your health care team if your condition is under control.

Still, for such a simple concept, it raises many questions. How often should you test? What time of the day should you do it? You and your doctors will work closely together to find the answers that will keep you healthy.

Setting Goals

You’re shooting for an A1c level of 7% or less, which equals an average glucose (or eAG) of 154 mg/dL. Your doctor will give you an A1c test every 3-6 months.

When you should test and what goals you’re aiming for depend on:

  • Your personal preferences
  • How long you’ve had diabetes
  • If you’re pregnant
  • Your age
  • Other health problems you may have
  • Medicines you’re taking
  • If you have complications like retinopathy or neuropathy
  • If you have low blood sugar (your doctor may call this hypoglycemia) without warning signs

Testing Times

Once you and your doctors figure out where your levels should be and the best way to get there (through diet, exercise, or medications), you’ll decide when you should check your blood sugar.

A fasting blood glucose level (FBG), taken in the morning before you eat or drink anything, is the go-to test for many. Another test at bedtime is common.

But what about other times? Testing 1 to 2 hours after breakfast or before lunch gives a more complete picture of what’s going on, says Pamela Allweiss, MD, of the CDC.

The American Diabetes Association says testing right after a meal can provide your doctor with good info when your pre-meal blood-sugar levels are OK but you haven’t reached your A1c goal.

“Monitoring is really important, particularly if you take insulin or medicine that can cause hypoglycemia,” says David Goldstein MD, professor at the University of Missouri School of Medicine. And measuring both before and after meals is important in understanding what your blood-sugar patterns are and what to do about them.

This switch is part of a move away from a kind of one-size-fits-all thinking and toward more individualized care.

Why? The old mantra was that better control led to fewer complications, Allweiss says. And that works OK for people who are healthy despite the diabetes. But then doctors figured out that tight control of the disease might not be safe for people with other conditions like heart disease.

Tracking Trends

All this testing means nothing if you don’t keep track of the results. Many glucose meters now do that for you. You can also keep a log. A full lifestyle diary that includes your eating and exercise habits, and how you feel at different times of the day, can also be a big help.

There’s lots to monitor and lots to learn. Your self-testing is a big part of it. One number doesn’t tell the story.

A number by itself is just a number, Allweiss says. “We want to look at a pattern.”

The steps to take after testing, of course, are simple enough: Talk to your doctors, learn what all those numbers mean, and figure out how you can meet your blood-sugar goals.

“Diabetes requires a lot of education. It isn’t like taking a pill and seeing a doctor twice a year. You have to be engaged,” Goldstein says. “We have great tools now, and we need to teach people how to use them. People have to know what to do -- and then they have to do it.”

Show Sources


American Diabetes Association: “Checking Your Blood Glucose.”

American Diabetes Association: “A1c and eAG.”

University of Maryland School of Pharmacy: “What is New in the ADA Guidelines? Blood Glucose Monitoring.”

Joslin Diabetes Center: “Goals for Blood Glucose Control.”

Joslin Diabetes Center: “When to Test Blood Glucose.”

The American Diabetes Association: “Standards of Medical Care in Diabetes -- 2015.”

Pamela Allweiss, MD, CDC, Atlanta

The American Diabetes Association: “Blood Glucose Log.”

David Goldstein, MD, adjunct professor of clinical child health, University of Missouri School of Medicine.

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