Blood glucose levels can be measured easily at home or anywhere.
A fingerstick glucose test is most often used to monitor blood glucose. Most blood glucose monitoring devices (glucose meters) use a drop of blood obtained by pricking the tip of the finger with a small lancet. The lancet holds a tiny needle that can be jabbed into the finger or placed in a spring-loaded device that easily and quickly pierces the skin. Most people find that the pricking causes only minimal discomfort. Then, a drop of blood is placed on a reagent strip. The strip contains chemicals that undergo changes depending on the glucose level. The glucose meter reads the changes in the test strip and reports the result on a digital display. Some devices allow the blood sample to be obtained from other sites, such as the palm, forearm, upper arm, thigh, or calf. Home glucose meters are smaller than a deck of cards.
Continuous glucose monitoring (CGM) systems use a small glucose sensor placed under the skin. The sensor measures blood glucose levels every few minutes. There are two types of CGMs, with different purposes:
Professional CGMs collect continuous blood glucose information over a period of time (72 hours to up to 14 days). Health care providers use this information to make treatment recommendations. Professional CGMs do not provide data to the person with diabetes.
Personal CGMs are used by the person and provide real-time blood glucose data on a small portable monitor or on a connected smart phone. Alarms on the CGM system can be set to sound when blood glucose levels drop too low or climb too high, so the device can help people quickly identify worrisome changes in blood glucose.
Previously, CGMs required frequent calibration with fingerstick glucose testing. Also their results were not accurate enough so that people always had to do a fingerstick to verify a reading on their CGM before calculating a dose of insulin (for example, before meals or to correct a high blood sugar). However, recent technological advances have improved CGMs and promise to continue doing so for the foreseeable future. They can now be worn for up to 14 days, often do not require calibration, and can be used for insulin dosing without fingerstick glucose confirmation. Finally, there are now systems in which the CGM device communicates with insulin pumps Insulin Replacement Therapy Many people with diabetes require drugs to lower blood glucose levels, relieve symptoms, and prevent complications of diabetes. There are two types of diabetes mellitus Type 1, in which the… read more to either stop delivery of insulin when blood glucose is dropping (threshold suspend), or to give daily insulin (hybrid closed loop system).
CGM systems are particularly helpful in certain circumstances, such as in people with type 1 diabetes who have frequent, rapid changes in blood glucose (particularly when the glucose levels sometimes go very low), which are difficult to identify with fingerstick testing.
Most people with diabetes should keep a record of their blood glucose levels and report them to their doctor or nurse for advice in adjusting the dose of insulin or the oral antihyperglycemic drug. Many people can learn to adjust the insulin dose on their own as necessary. Some people who have mild or early type 2 diabetes that is well-controlled with one or two drugs may be able to monitor their fingerstick glucose levels relatively infrequently.
Although urine can also be tested for the presence of glucose, checking urine is not a good way to monitor treatment or adjust therapy. Urine testing can be misleading because the amount of glucose in the urine may not reflect the current level of glucose in the blood. Blood glucose levels can get very low or reasonably high without any change in the glucose levels in the urine.