Test Overview

A home blood sugar test measures the amount of a type of sugar, called glucose, in your blood at the time of testing. The test can be done at home or anywhere, using a small portable machine called a blood glucose meter.

Home blood sugar testing can be used to monitor your blood sugar levels. Talk with your doctor about how often to check your blood sugar. How often you need to check it depends on your diabetes treatment, how well your diabetes is controlled, and your overall health. People who take insulin to control their diabetes may need to check their blood sugar level often. Testing blood sugar at home is often called home blood sugar monitoring or self-monitoring.

If you use insulin rarely or don't use it at all, blood sugar testing can be very helpful in learning how your body reacts to foods, illness, stress, exercise, medicines, and other activities. Testing before and after eating can help you adjust what you eat.

Some types of glucose meters can store hundreds of glucose readings. This allows you to review collected glucose readings over time and to predict glucose levels at certain times of the day. It also allows you to quickly spot any major changes in your glucose levels. Some of these systems also allow information to be saved to a computer so that it can be turned into a graph or another easily analyzed form.

Some newer models of home glucose meters can communicate with insulin pumps. Insulin pumps are machines that deliver insulin through the day. The meter helps to decide how much insulin you need to keep your blood sugar level in your target range.

Why It Is Done

If you have diabetes, testing your blood glucose levels at home provides information about:

• Your blood sugar level at the time of testing. It is important to know when your blood sugar is high or low, to prevent emergency situations from developing. It is also important to treat consistently high blood sugar levels so you can decrease your chances of developing heart, blood vessel, and nerve complications from diabetes.
• How much insulin to take before each meal. If you take rapid-acting or short-acting insulin before meals, the blood sugar test results can help you determine how much insulin to take before each meal. If your blood sugar level is high, you may need extra insulin. If your blood sugar level is low, you may need to eat before you take any insulin.
• How exercise, diet, stress, and being ill affect your blood sugar levels. Testing your blood sugar can help you learn how your body responds to these things. Where possible, you can adjust your lifestyle to improve your blood sugar level.

Home blood sugar testing also may be used to:

• Decide on an initial insulin dose and schedule or to adjust the insulin doses or schedule.
• Test blood sugar levels in people who have symptoms of high blood sugar (hyperglycemia) or low blood sugar (hypoglycemia).

How To Prepare

The supplies you will need for testing blood sugar include:

• A blood glucose meter.
• Testing strips. These are made to be used with a specific model of meter. Make sure the strips haven't expired.
• Sugar control solutions. Some meters require a specific solution. Many new meters are made to operate without a control solution.
• Short needles called lancets for pricking your skin.
• A pen-sized holder for the lancet (lancet device). It positions the lancet and controls how deeply it goes into your skin.
• Clean cotton balls. These are used to stop the bleeding from the testing site.

How It Is Done

Checking your blood sugar involves pricking your finger, palm, or forearm with a lancet to collect a drop of blood. The blood drop is placed on a test strip, which you insert into the blood glucose meter. The instructions for testing are slightly different for each blood glucose meter model. Follow the instructions that came with your meter.

• Wash your hands with warm, soapy water. Dry them well with a clean towel. You may also use an alcohol wipe to clean your finger or other site. But make sure your hands are dry before the test.
• Insert a clean lancet into the lancet device.
• Remove a test strip from the test strip bottle. Replace the lid right away to keep moisture away from the other strips.
• Follow the instructions that came with your meter to get it ready.
• Use the lancet device to stick the side of your fingertip with the lancet. Do not stick the tip of your finger. Some blood sugar meters use lancet devices that take the blood sample from other sites, such as the palm of the hand or the forearm. But the finger is usually the most accurate place to test blood sugar.
• Put a drop of blood on the correct spot on the test strip.
• Apply pressure with a clean cotton ball to stop the bleeding.
• Follow the directions that came with the meter to get the results.
• Write down the results and the time that you tested your blood. Some meters will store the results for you.

How long the test takes

The blood glucose meter will show the results of the test in a minute or less.

How It Feels

Your fingertips may get sore from frequent pricking for blood sugar testing. But there are things you can do to prevent soreness. For example, prick the side of your finger, not the tip. Don't squeeze the tip of your finger. And use a different finger each time. You can also try a different meter that uses blood from somewhere other than the fingers.

Risks

There is very little risk of complications from testing your blood with a home blood sugar monitor.

• You may get an infection in your finger if you do not wash your hands before sticking your finger.
• You may get hardened areas on your fingertips from frequent blood sugar testing. Use lotion to help soften these areas.

Results

Diabetes Canada recommends that you stay within the following blood glucose level ranges.^{footnote 1, footnote 2} But depending on your health, you and your doctor may set a different range for you.

For most adults (non-pregnant)

• 4.0 to 7.0 millimoles per litre (mmol/L) before a meal
• 5.0 to 10.0 mmol/L 2 hours after a meal

For women who have diabetes and are pregnant

• Less than 5.3 mmol/L before a meal
• Less than 6.7 mmol/L to 7.8 mmol/L 1 to 2 hours after a meal