Blood glucose monitoring is a routine practice for managing conditions like diabetes, relying on lancets and test strips. A lancet is a sterile, single-use needle contained within a lancing device, which is used to obtain a tiny drop of capillary blood. Test strips are small plastic strips containing a chemical reagent that interacts with the blood sample, allowing a specialized meter to measure the concentration of glucose. This empowers individuals to make informed decisions about diet, activity, and medication.
Setting Up the Testing Equipment
Before performing a test, the equipment must be prepared to ensure an accurate reading. Check the blood glucose meter’s battery life and verify that the test strip vial has not expired, as the chemical reagents degrade over time. If your meter requires manual coding, confirm that the code on the meter’s screen matches the code printed on the strip vial.
The lancing device requires a new lancet for each use, as dulling occurs after just one puncture. Remove the cap of the lancing device and firmly insert a fresh lancet, then twist off and save the small protective cap on the lancet needle. Replace the lancing device cap and adjust the depth setting, which controls how far the needle penetrates the skin. A setting of two or three is often a good starting point, and can be adjusted based on skin thickness.
Take one test strip from the container and immediately close the cap tightly to protect the remaining strips from moisture. Insert the strip into the meter until it clicks or the meter turns on and displays a prompt, such as a flashing blood drop icon. The meter is now ready to receive the sample.
The Process of Obtaining a Blood Sample
Proper hygiene is the first step in obtaining a clean and accurate blood sample. Wash your hands thoroughly with soap and warm water and dry them completely. Warming the hands increases blood flow. Avoid using alcohol wipes immediately before testing, as any residual alcohol can interfere with the test strip’s chemical reaction and distort the result.
Select a testing site on the side of a fingertip, rather than the sensitive central pad. The ring and middle fingers are generally preferred over the thumb and index finger, which are often calloused and more frequently used. Press the loaded lancing device firmly against the chosen spot, then press the release button to execute the quick, shallow puncture.
After the lancet has pricked the skin, gently massage the finger from the base toward the tip to encourage a sufficient drop of blood to form. Avoid excessively squeezing the finger, as this action can draw interstitial fluid from the surrounding tissue into the sample, potentially causing an inaccurate or falsely low reading.
Applying the Sample and Reading Results
Carefully bring the tip of the strip to the edge of the blood drop. The strip’s specialized wicking channel will automatically draw the required volume of blood into the reaction area through capillary action. Do not smear the blood onto the strip or apply it to any area other than the designated sample port.
Once the meter detects sufficient blood, it will begin a short electronic countdown. If the meter displays an error message or a flashing blood drop icon after the initial contact, it often indicates that the sample volume was inadequate. Some meters allow a short window to apply more blood to the same strip before requiring a new test.
After the countdown finishes, your blood glucose value will appear on the meter’s display. The result will remain visible until you remove the test strip or the meter automatically powers off.
Safe Handling and Disposal
The used lancet and test strip must be handled safely to prevent accidental needle-stick injuries. Remove the lancing device cap and carefully eject the used lancet, often by using a built-in release mechanism or by pushing the exposed needle into the protective cap that was saved during the setup process. The used test strip should be pulled straight out of the meter.
The lancet must be placed into a dedicated sharps container immediately. If a commercial sharps container is not available, a heavy-duty, puncture-proof plastic container with a secure, tight-fitting lid, such as a laundry detergent bottle, can be used as a temporary measure. Never dispose of used lancets directly into the regular trash or recycling bin, as this poses a significant risk to sanitation workers.
Once the sharps container is about three-quarters full, disposal of the container must follow local regulations. This often involves dropping it off at a pharmacy, medical office, or designated hazardous waste collection site. The used test strip can generally be discarded with regular household waste.