A glucometer is a medical device used to measure the concentration of glucose in a blood sample. For individuals with diabetes, it is a common tool for managing their condition. Monitoring blood glucose helps people track the effects of food, exercise, stress, and medication on their blood sugar levels. This information allows for timely adjustments to treatment plans to maintain health and prevent complications.
How Glucometers Work
Most modern glucometers operate using electrochemical technology. The process begins when a disposable test strip is inserted into the meter. These test strips are coated with a thin layer of enzymes, such as glucose oxidase or glucose dehydrogenase. When a small drop of blood is applied to the strip, the glucose in the blood initiates a chemical reaction with the enzymes.
This reaction involves the oxidation of glucose, which removes electrons from the glucose molecules. A mediator chemical then transports these electrons to an electrode within the test strip, generating a small electrical current. The glucometer measures the strength of this current; a stronger current corresponds to a higher amount of glucose in the blood. The meter then uses this measurement to calculate and display the blood glucose concentration.
Types of Glucose Monitoring Systems
Glucose monitoring systems fall into two primary categories: traditional blood glucose meters (BGMs) and continuous glucose monitors (CGMs). BGMs, often called “finger-prick” devices, provide a snapshot of blood glucose at the specific moment of testing. They require a small blood sample obtained with a lancet and applied to a test strip.
Continuous glucose monitors represent a newer approach to tracking glucose levels. A CGM system uses a small sensor inserted just under the skin, typically on the arm or abdomen, which measures glucose levels in the interstitial fluid. A transmitter sends this data wirelessly to a receiver or smartphone, providing readings every few minutes. This offers a dynamic view of glucose trends, showing whether levels are rising, falling, or stable.
A distinction between these systems is what they measure. BGMs analyze glucose directly from capillary blood, while CGMs measure it in interstitial fluid. Because glucose moves from the blood into the interstitial fluid, there can be a slight delay, or “lag time,” of 5 to 15 minutes in CGM readings compared to BGM results. This lag is most noticeable during periods of rapid glucose change.
Factors in Selecting a Glucometer
Choosing a glucose monitoring system involves balancing practical needs and personal preferences. One of the primary considerations is cost and insurance coverage. It is important to check with an insurance provider, as some plans may only cover specific models or limit the number of test strips they will pay for. The initial price of the meter is a one-time expense, but the recurring cost of supplies represents the bulk of the long-term expense.
Device features also play a role in the selection process. Some users may prefer a meter with a large, backlit screen for better visibility. Other features to consider include memory storage to track test results over time, and Bluetooth connectivity that allows the meter to sync with a smartphone app. The physical design, such as the size of the meter and the ease of handling the test strips, can also impact daily use.
The amount of blood required for a sample is another factor, with some meters needing as little as 0.3 microliters. While all commercially available meters must meet established accuracy standards, users concerned about precision can research independent reviews. The best meter is one that fits an individual’s lifestyle and is used consistently.
Proper Glucometer Usage and Technique
To ensure an accurate reading from a traditional blood glucose meter, proper technique is necessary. Begin by gathering all supplies and washing hands thoroughly with soap and warm water to remove any residue. If handwashing isn’t possible, an alcohol swab can be used, but the finger must be completely dry before testing.
Next, prepare the lancing device by adjusting its depth setting, and insert a fresh test strip into the meter. It is generally less painful to prick the side of a fingertip rather than the pad. After lancing, a small drop of blood should form without squeezing the finger excessively, as this can dilute the sample and affect the result.
Gently touch the edge of the test strip to the blood drop, allowing the strip to draw in the necessary amount of blood. The meter will then process the sample and display the reading within a few seconds. The used lancet and test strip should be disposed of safely in a sharps container. For continued accuracy, store test strips in their original sealed container and be mindful of their expiration dates.