Tips for Testing Your Blood Glucose (Blood Sugar)

  • 3 Minutes Read
Katherine Isacks
Katherine Isacks, MPS, RDN, CDCES - Registered Dietitian and Certified Diabetes Care and Education Specialist (CDCES)

Are you using proper technique to get an accurate blood glucose (BG) reading at home? Be sure you know the basics of good technique so that you can avoid frustrating swings in readings that seem unrelated to your food intake, exercise, or medication schedule.

Tips for Testing Your Blood Glucose (Blood Sugar)

Are you using proper technique to get an accurate blood glucose (BG) reading at home? Be sure you know the basics of good technique so that you can avoid frustrating swings in readings that seem unrelated to your food intake, exercise, or medication schedule.

When to Test

Resist the urge to test at random times - you will only waste expensive strips, cause unnecessary anxiety, and possibly increase the likelihood of having a low BG if you don't understand appropriate BG goals. The testing times and BG goals listed below are associated with a Hemoglobin A1C value of less than 7% - that goal has a lower risk of diabetes complications such as eye, kidney, and nerve damage. Depending upon your diagnosis and medication schedule, you might be testing at some of these times or perhaps at all of these times. BG goals are from the American Diabetes Association unless otherwise stated. If you have diabetes and have been instructed by your care team to test on a certain schedule, then continue to do that.

Fasting. Goal 80 mg/dL - 130 mg/dL. Take your BG after waking up, after having no food or drink for at least 8 hours (water okay). This is usually the same as your "before breakfast" reading.

Before meals. Goal 80 mg/dL-130 mg/dL. This assumes you have not had food or drink (except water) for the prior 2-3 hours before testing.

After meals: test 1-2 hours after the first bite of your meal. Goal < 180 mg/dL. This is also called post-prandial glucose or PPG.

Bedtime. Goal 100 mg/dL - 150 mg/dL. This range is appropriate for adults who take insulin or a diabetes medication with a higher risk of hypoglycemia (e.g. sulfonylurea or meglitinides).

When You Feel Low. If you are experiencing the symptoms of hypoglycemia then test your BG to confirm and then treat using the 15/15 rule. If you are having repeated lows, call your doctor for help in getting your food, exercise, and diabetes medication coordinated for safer BG control. Repeated lows are NOT safe.

Where to Test

Sides of your fingertips. The sides of your fingertips will hurt less than poking the fingertip pads. Although many BG meters allow "alternate site testing" - be sure to use your fingertip sides if you are testing to confirm hypoglycemia and/or if you are testing to confirm that you have brought your BG up to a safe level.

How to Test

Wash your hands with warm soapy water and dry with a clean cloth or paper towel. This is the preferred method to clean off debris that can cause a falsely high reading and it is more effective than swiping with an alcohol pad. A lot of substances can cause a high reading - always wash your hands before testing!

Gently swing your arm to help encourage the blood to move into the fingers -this will help get a good blood drop.

Insert the blood glucose strip into your meter. Watch it turn on and make sure the code matches the strip container if that applies to your meter (typically for older meters).

Poke the side of your fingertip with an unused lancet in the lancet device. Used lancets get blunt so they hurt more than new ones. If you don't get a good drop, you might need to make the poke deeper. Find the dial on the lancet device that increases poke depth - it is often displayed with small to large dots. If you still need help getting the blood drop a little bigger, then you can milk your finger starting from its base. Avoid squeezing your fingertip for more blood - the milking action is more effective.

Hold your meter so that the strip "sips" your blood like a straw. Don't smear your blood on the strip area.

Meter display. When the BG reading appears, does it also display the correct date and time? If not, then go into your meter settings and correct it. You need an accurate time stamp for your BG records. BG meters should have a toll free number on the back for help with using the meter.

Equipment Basics

BG meter. Most meters have a shelf life of about 5 years - maybe less. Brands have different attributes - what is important to you? Big display? Small size? Requires less blood to read? Longer time delay between strip insertion and required blood drop? If you have insurance that covers a BG meter and strips, then try to use the brand that is covered.

BG strips. Use clean, unused strips that have not expired (check container for expiration date). Keep strips container closed and store at room temperature. Strips and meters can get damaged by extreme temperatures or by exposure to moisture. Only use strips that go with your BG meter. Strips are the most expensive component due to the number required over time.

Lancet device: this is the device that holds the lancet (the little metal needle that pokes you).

Lancet: this is the little metal needle that pokes you. Use lancets that are thin enough to be comfortable for your fingertip sides. Lancets go with specific lancet devices. Always use a new lancet with every poke for the least discomfort. Lancets are the least expensive component.

Container for used strips and lancets. You can put used strips and lancets in those hard plastic medication containers for regular trash disposal. However, if you use a biohazard container, then you must dispose of this container according to regulations where you live to avoid a penalty.

Control Solution. This is a glucose solution that should test within a certain BG range specified on the BG strips container. If you suspect your meter or strips are bad, then test the control solution to see if the reading is within the specified range. Temperature extremes ( checked luggage), exposure to moisture, and simple expiration can cause incorrect readings. Discard strips and replace meter if necessary.

BG testing in combination with food, exercise, and medication tracking is a very powerful way to fully understand and control your diabetes. Try MyNetDiary Diabetes Tracker to see how it all fits together.

Diabetes->Blood glucose
Aug 12, 2014

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