Glucose Monitoring Devices
What is blood glucose monitoring?
Blood glucose levels (also called blood sugar levels) reflect how well diabetes is
being controlled and how well the plan of care (diet, exercise, and medicine) is working.
If the blood sugar levels are consistently under control (with levels near normal),
diabetes complications may be reduced or even prevented.
How can blood sugar levels be checked?
Checking blood glucose levels regularly is very important in proper diabetes management.
Current methods of blood sugar monitoring require a blood sample. Blood sugar monitoring
can be done at home with a variety of invasive devices to obtain the blood sample
(invasive means the penetration of body tissue with a medical instrument).
Usually a drop of blood obtained through a finger prick is enough to use on a test
strip that is then measured in a monitor. A finger prick can be done with a small
lancet (special needle) or with a spring-loaded lancet device that punctures the fingertip
quickly. The strip goes into the meter first, then a drop of blood is placed on the
tip of the strip (also called a glucose meter or glucometer) that reads the blood
There are many types of monitors on the market today. They range in price, ease of
use, size, portability, and length of testing time. Each monitor needs its own type
of testing strip. Most blood glucose monitors have been found to be accurate and reliable
if correctly used, and most monitors give results within seconds. Some glucose monitors
can also give verbal testing instructions and verbal test results for people who are
visually or physically impaired. There are also glucose monitors available that provide
verbal instructions in Spanish and other languages.
New monitoring systems are becoming available that can monitor blood sugar continuously
for several days at a time. Users can set alarms so they can be warned if their sugars
get too low or too high.
People with diabetes may have to check their blood sugar levels up to 4 or more times
a day. Blood sugar levels can be affected by several factors, including the following:
Certain blood glucose monitors are equipped with data-management systems. This means
your blood glucose measurement is automatically stored each time. Some healthcare
providers' offices have computer systems compatible with these data-management systems,
which allows the blood sugar level recordings, and other information, to be transferred
electronically. This can be done at your home computer as well. One advantage of a
data-management system is the ability to plot a graph on the computer depicting patterns
of blood sugar levels.
What are noninvasive blood glucose monitors?
A finger prick can become painful and difficult for a person with diabetes to do on
a regular basis. Several noninvasive devices (that do not need an actual blood sample)
are currently being researched to give people with diabetes an alternative. However,
most noninvasive blood glucose monitoring devices have not yet been approved by the
FDA. Some noninvasive devices currently under investigation include:
The use of infrared light to shine through the forearm or finger
The use of low-level electrical currents to draw blood up through the skin
The use of saliva or tears to measure glucose levels
To make sure that monitors are approved for use, the National Institute of Diabetes
and Digestive and Kidney Diseases suggests that consumers call the FDA at 888-INFO-FDA (463-6332). You can also check the FDA's website Blood Glucose Monitoring Devices section.
What are healthy blood sugar level ranges?
Blood sugar levels over 200 mg/dl (mg/dl = milligrams of glucose per deciliter of
blood) or under 70 mg/dl are considered unhealthy. High blood sugar levels (above
200 mg/dl) may be a sign of inadequate levels of insulin, caused by overeating, lack
of exercise, or other factors. Low blood sugar levels (below 70 mg/dl) may be caused
by taking too much insulin or other diabetes medicines, skipping or postponing a meal,
overexercising, excessive alcohol consumption, or other factors.
> 200 mg/dl
Too high; considered unhealthy
70 - 130 mg/dl
Good range for most people
< 70 mg/dl
Too low; considered unhealthy
The American Diabetes Association (ADA) recommends a preprandial (before a meal) plasma
glucose level of 70 mg/dl to130 mg/dl. The ADA has set the postprandial (after a meal) plasma
glucose level of less than 180 mg/dl.
The following are the most common symptoms of hyperglycemia (high blood sugar). However,
there may be no symptoms, and each individual may experience symptoms differently.
Symptoms may include:
The following are the most common symptoms of hypoglycemia (low blood sugar). However,
each individual may experience symptoms differently. Symptoms may include:
Sometimes, none of these warning symptoms appear before a person loses consciousness
from low blood glucose. The loss of the ability to sense low blood sugar is called
Insurance and blood glucose monitoring
Be sure to check with your insurance company to determine if blood glucose monitoring
equipment and testing supplies are covered under your plan. If not, many suppliers
offer rebates and/or discounted prices on trade-ins.
In addition, when selecting a glucose meter, the ADA reminds consumers to factor in
the ongoing cost of test strips. Test strips can cost between 50 cents and one dollar per
strip. Insurance providers vary on how many strips and how much of the test strip
cost they will cover.