Living With Diabetes: How to Test Blood Glucose/Blood Sugar

Living with diabetes requires checking blood glucose levels (aka blood sugar). Your doctor will likely require you to test your levels at least once per day. For people with Type 1 diabetes, more frequent testing is required so that insulin dosages can be closely tailored to food intake, exercise and more. Type 2 diabetics also need to test blood to make dietary and exercise adjustments, and to determine whether medications are effectively working to help lower glucose levels.

Home diabetes tests require use of a blood sugar meter, diabetes test strips and a lancet device. The meter itself is about the size of a small cell phone. Test strips are usually inserted, one at a time, at the top or bottom of the meter. The patient then uses the lancet to prick a finger, the heel of the hand, or forearm to draw a small bead of blood. Placing the test strip against the bead, the blood is "sucked" in, like a straw, and a measure of the amount of glucose currently in the person's bloodstream is displayed after the meter makes its calculations.

In the United States, a blood sugar level is usually displayed as a measure of milligrams per deciliter (mg/dL). A normal range in a non-diabetic person is approximately 80-120 mg/dL. Dangerously high blood sugar levels (hyperglycemia) occur over 200 mg/dL. Hypoglycemia, on the other hand, is generally defined as a level at or lower than 70 mg/dL. When blood glucose levels are high, insulin must be administered. When levels are low, the patient must consume carbohydrates immediately, preferably in the form of juice or sugar (non chocolate) candy.

Testing blood glucose when you have diabetes is the most efficient means of determining whether and how to treat highs or lows to prevent medical emergencies and to avoid long-term damage from unmanaged diabetes. A diabetic should always have his or her meter and other blood glucose testing supplies close at hand when traveling, recreating, going to work or to school.

If you or a loved one has diabetes, your doctor may prescribe a specific type of blood glucose meter for your home use. There are many meters on the market, and insurance will usually cover the cost. Some meters can be set up to communicate via radio signals to your insulin pump, which will then calculate the amount of insulin required at that time.

A lancet is the "poking" device and is spring-operated. The patient can adjust the force with which the small needle pierces the skin. Over time, some test sites can become calloused and require a stronger poke to draw blood. Fingers are usually used to test blood glucose, but the heel of the hand is another good alternative. Some meters allow for testing on other areas of the body, as well. Discuss the options with your medical team in making a decision.

Although meters and lancets are not usually expensive or difficult to obtain (your doctor may have a free one to provide), insurance companies closely monitor the number of diabetes test strips prescribed to you. If you have too many errors or test too frequently, you may run into issues when you go to refill your prescription!

Be sure to discuss this matter with your doctor in advance. He or she may need to contact your insurance company directly to ensure you are provided sufficient strips for the duration of your prescription.

• Thoroughly wash and dry hands, preferably using warm water. You will need to remove traces of meals, dirt and bacteria before testing
• Make sure your hands are warm enough before testing. If not, run under warm water or rub together vigorously
• Take the meter and insert a new diabetes test strip
• Wait for the display that indicates the meter is ready to read a drop of blood
• Use a new lancet each time you test to prevent infection
• Prepare the test area (usually a fingertip) with an antiseptic wipe for best results; allow to dry first
• With the lancet, make sure that the dial is at the setting you prefer. Most are adjustable, with a light poke (level 1) to a deeper poke (level 5). Personally, I keep my lancet at a level 3 or 4. Place the lancet firmly against the skin and hold tightly while pressing the trigger
• Place the lancet device firmly against the skin and hold in place while depressing the trigger
• If a small droplet of blood appears, "milk" it to increase size slightly to ensure an accurate test. Place the edge of the test strip against the droplet of blood and ensure that the entire strip is "filled" for a complete test
• If the initial application of the lancet does not draw sufficient blood, prepare a new site on a different finger or location and try again
• Use test sites with fewer nerves than the pad of the fingertip. I use the sides of my fingers, and others have good results with the heel of their hand or forearm
• Your meter will also be sensitive to temperature extremes. If it gets too hot or too cold, it will not function properly. Take appropriate measures to shade it during summer, or keep in a pocket during winter
• Most blood glucose meters will display a reading (accurate to +/- 10%) within 10-20 seconds.