Home Glucose Testing: How to Do It and Interpret Results

Monitoring your blood sugar regularly at home can be an important part of your diabetes management. At home blood glucose testing can prevent serious complications resulting from consistently high blood sugar:

Heart disease

People with Type 2 diabetes are more likely to develop and die from cardiovascular diseases, such as heart attacks, strokes and heart failure, than people who don’t have diabetes.[1] This is because high blood sugar damages heart blood vessels and nerves.

Chronic kidney disease

In the United States about 1 in 3 people with diabetes have diabetic nephropathy, which is chronic kidney disease (CKD).[2] It occurs because diabetes damages blood vessels and other cells in the kidneys that filter waste from blood. This can lead to kidney damage and high blood pressure.

Diabetic Retinopathy

The condition occurs when high blood sugar damages blood vessels in the retina, which is the light-sensitive layer of cells in the back of the eye.  The damaged blood vessels can swell and leak. The result is blurry vision or blood flow stops. New blood vessels may grow, but they are not normal and can cause further vision problems. The condition usually affects both eyes.

Nerve damage: Neuropathy is a common complication of diabetes that can affect the nerves that control movement, sensation, and other functions. Peripheral neuropathy is common among diabetics. The National Institute of Health (NIH) National Institute of Diabetes and Digestive and Kidney Disease (NIDDK) estimates up to one-half of people with diabetes have the condition due to high blood glucose or blood sugar.[3] That’s because high blood glucose or blood sugar and high levels of fats in the blood from diabetes can damage nerves and the small blood vessels that nourish nerves, leading to peripheral neuropathy.

When glucose monitoring matters

Not everyone with diabetes will need to test their blood at home, and your medical provider will advise you if home glucose testing is necessary. Conditions that require you to conduct home testing include: [4]

• Take insulin or other medications that can cause low blood sugar or hypoglycemia. 
• Have trouble controlling your blood sugar.
• Suspect you have low blood sugar because of symptoms: headache, sweating, hunger, jitteriness, confusion, dizziness, irritability, weakness, or a fast or irregular heart rate.
• Experience low blood sugar without warning signs.
• Have ketones from high blood sugar.
• Are sick.
• Are pregnant.

Home glucose blood test with a glucose meter

It is not difficult to track your blood sugar. You can monitor your blood sugar with a glucose meter and finger stick. With this method, you produce a blood drop by pricking your fingertip with a small needle called a lancet. You then place the drop against the test strip in the glucose meter. Within a few seconds, the meter shows your blood sugar level.  Since finger sticks only measure blood glucose at one moment in time, you may have to check your blood several times a day.

How often you need to check your blood sugar each day depends on the type of diabetes you have, the type of medicine you take, and how well your blood sugar levels are controlled. Your doctor will personalize the testing schedule for you, which might include testing:

·         in the morning when you wake up

·         prior to eating a meal

·         2 hours following a meal

·         at bedtime

·         with signs of high or low blood sugar

·         during and after exercise

Steps to take for blood glucose test:

• Wash and dry your hands.
• Place a test strip into the meter.
• Prick your finger with the lancet to get a drop of blood.
• Apply a drop of blood to the test strip and wait for the results.
• After each test, record the test result.

For people with diabetes, blood sugar readings should be:

·         Before meals: 80 to 130 milligrams per deciliter (mg/dL)

• Roughly 2 hours after a meal begins: less than 180 mg/dL.

Before you begin home glucose testing, get target figures from your doctor. Target figures may change over time based on your health, age, weight, and other factors.

Glucose testing with a CGM

You also may choose to use a continuous (real-time) glucose monitor (CGM) or an intermittently scanned glucose monitor, which measures blood sugar every few minutes.

Real-time CGMs

These systems are made up of three components: the sensor (a small wire catheter that is inserted under the skin on your arm or abdomen), a transmitter that attaches to the sensor, and a handheld receiver and/or smartphone that displays your glucose data in real time. A real-time CGM has an audible alarm that can warn you when your blood sugar is getting too high, which gives you time for adjustments to reduce the impact of high or low blood sugar or avoid it.  Real-time CGMs transmit data continuously and let you share data with others, such as family members and friends. This is valuable if you are traveling. Some also enable you to eliminate the need for finger stick confirmation to make treatment decisions. [5]

Intermittently scanned CGMs

An intermittently scanned CGM uses two components: a combined glucose sensor/transmitter (inserted in your upper arm) and a separate touchscreen reader device. The sensor continuously samples and measures glucose, generates a new glucose value every minute, and records the reading every 15 minutes for 10 to 14 days of sensor wear time, depending on the model. The devices are convenient and easy to use and enable you to share data with family, friends and caregivers or health care providers via smartphones. Some also enable you to make treatment adjustments without the need for confirmation from a finger stick. [6]

Monitoring your blood glucose helps manage your diabetes. You will want to consult with your doctor about unusually high results, particularly if they happen on more than one occasion. You may need to make changes to your lifestyle, such as different foods and more exercise, as well as changes to your medication.