How do I check my blood sugar levels if I have diabetes?

Unfortunately, you still need to prick your finger to test your blood sugar. In this video, Ronald Tamler, MD, clinical director of the Mount Sinai Diabetes Center, talks about home testing of diabetes.

If you have diabetes, to keep track of your blood sugar (glucose) levels, you can use a blood glucose meter. It’s super simple to use. Prick the skin on your fingertip with a tiny needle. Press the drop of blood onto a test strip, and the meter will test it and give you your blood glucose level.

Intermountain Registered Dietitians
Nutrition & Dietetics Specialist

Your doctor or diabetes educator will tell you when and how often to check your blood glucose levels. This is the only way you can know how much insulin or food to take at different times. To check your blood glucose, you need to prick your finger to get a tiny sample of blood, then use a small machine called a glucose meter to read the sample and display your blood glucose level. There are many different meter models to choose from. Your doctor or diabetes educator will help you get a meter and show you how to use it. It may take some practice. Follow the directions that come with your meter.

Tips for tracking:

  • Be consistent: Make it a habit to record each blood glucose reading and each insulin dose.
  • Be complete: Most logs have a place to write notes. Use that space to write down changes in your routine, how you feel, whether you had ketones, etc. This extra information can help your diabetes care team assess your treatment.
  • Watch for trends: Circle any blood glucose readings that are too high or too low. Can you see a pattern as to when these readings occur? (For example, do you tend to have lows after soccer practice on Tuesdays and Thursdays?) Discuss this with your care team.

Here's how to check your blood glucose level with a glucose meter:

  1. After washing your hands, insert a test strip into your meter.
  2. Use your lancing device on the side of your fingertip to get a drop of blood.
  3. Gently squeeze or massage your finger until a drop of blood forms. (Required sample sizes vary by meter.)
  4. Touch and hold the edge of the test strip to the drop of blood, and wait for the result.
  5. Your blood glucose level will appear on the meter's display.

Note: All meters are slightly different, so always refer to your user's manual for specific instructions.

Other tips for checking:

  • With some meters, you can also use your forearm, thigh or fleshy part of your hand.
  • There are spring-loaded lancing devices that make sticking yourself less painful.
  • If you use your fingertip, stick the side of your fingertip by your fingernail to avoid having sore spots on the frequently used part of your finger.
William Lee Dubois

People with diabetes once had to test their urine to find out what their blood sugar had been hours before. Now we have these fancy little meters that can tell us in seconds what our blood sugar is right now!

I could write an entire book on meters, and maybe I will, but here are my take-home points. First, be grateful that you can test, instead of complaining that you have to. Second, never take a number personally. It's just a number. Remember that "bad" numbers are just good information that you need to act on. Third and fourth, don't always test at the same time of day; and don't test only when you think your numbers will be low.

Look, low numbers may be good for the ego—but if you only check first thing in the morning, before you eat, when you know your blood sugar is going to be at its lowest, you're cheating at solitaire. Finding your highest blood sugar numbers is the real name of the game now. I know that some of you are squeamish about high blood sugar, but I want you to change that mindset. I want you to try to find your highs—seek them out—and celebrate the victory when you discover where they're hiding.

High blood sugar needs to be fixed. But if you don't look for highs you can't find them. And if you don't find them you can't fix them.

Diabetes Warrior: Be your own knight in shining armor. How to stay healthy and happy with diabetes.

More About this Book

Diabetes Warrior: Be your own knight in shining armor. How to stay healthy and happy with diabetes.

You survived the first year: now there is more to learn... Knights? Dragons? Diabetes?! Yep, armed with a wickedly sharp sense of humor and a medieval metaphor, Taming the Tiger author William Lee...
Dr. Jack Merendino, MD

There is absolutely no “wrong” time to test, but there are conventions that are helpful to doctors and to people with diabetes. Knowing how blood sugar changes with meals is important both in helping to reinforce good eating habits and in allowing adjustment of meal-related insulin or oral medication. Therefore, before-meal and 2 hours after-meal testing will help you know whether things get out of control with eating. A test at bedtime or in the middle of the night may uncover dangerous hypoglycemia when you might not sense it.

Monitoring your blood sugar doesn't just help you pick the best meals, it also lets you know whether you're taking the right amount of medication to prevent a large spike in blood sugar after eating. And monitoring before bedtime and first thing in the morning will help you know if your meds are keeping your blood sugar in a good range overnight.

Your blood sugar monitor will clue you in to the effects of exercise. Does your blood sugar go up or down after a short walk, a long walk, an aerobics class, a jog, or any other form of exercise? Do you need to adjust your medicine to safely cover exercise? That's what your trusty monitor will reveal. During exercise, you'll be moving your body more, and that may mean you need less medication, whether you're taking insulin or any other diabetes drug. For some of you, the combination of diet and exercise could mean a dramatic decrease in medication or even that you can stop taking medication. However, your body's ability to make insulin tends to decrease as time passes, so even with the best diet and exercise regimen, your blood sugar levels may eventually rise again and you may need to increase or restart medications in order to keep them normal.

The Best Life Guide to Managing Diabetes and Pre-Diabetes

More About this Book

The Best Life Guide to Managing Diabetes and Pre-Diabetes

Bob Greene has helped millions of Americans become fit and healthy with his life-changing Best Life plan. Now, for the first time, Oprah's trusted expert on diet and fitness teams up with a leading...

Diabetes—especially uncontrolled or untreated—can significantly increase your risk of heart disease. A simple blood test can determine how much glucose (sugar) is in your blood. The normal, non-diabetic range for fasting blood glucose is from 70 to 100 mg/dL. If the level is over 126 mg/dL, it usually means you have diabetes. If you have diabetes, treating other risk factors for cardiovascular disease—such as hypertension and abnormal cholesterol levels—is particularly important.

Checking your blood glucose (blood sugar) is an important way to gauge how well you're managing your diabetes. How often you check typically depends on whether you're taking insulin or oral diabetes medications. Even for people who take no medications, it's always good to know what's going on in your body. Blood sugars are like light in a dark tunnel. It's information against your enemy. If you don't have information, you can't fight as well as you can. Are you going up? Are you doing well? It gives you a snapshot of how you're doing.

Continue Learning about Diabetes

About Diabetes and Glucose
About Diabetes and Glucose
When a person has diabetes, levels of glucose (also called blood sugar) are too high. Learn what is happening at the cellular level when a person has ...
Read More
How are weight and diabetes related?
Skyrocketing rates of diabetes are directly linked to America's burgeoning waistline. More than 85 p...
More Answers
How to Get the Best Possible Care for Your Diabetes
How to Get the Best Possible Care for Your DiabetesHow to Get the Best Possible Care for Your DiabetesHow to Get the Best Possible Care for Your DiabetesHow to Get the Best Possible Care for Your Diabetes
The right backup can help you live well and worry less about complications.
Start Slideshow
Is Integrative Medicine the Same as Alternative Medicine?
Is Integrative Medicine the Same as Alternative Medicine?

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.