Thirdly, always using the second drop of blood after washing the hands with soap and water (5). Furthermore, in one of these recommendations, patients are advised not to squeeze the finger to obtain a drop of blood as this could potentially influence the blood glucose concentration (3).
Squeezing or milking the finger can contaminate the sample and lead to inaccurate results. To prepare for testing, massage the finger you plan to use and squeeze gently from the base of the finger to the fingertip a few times.
You Squeeze Too Hard
If your hands are clean and dry, you can use the first drop of blood that comes from the finger prick. If for some reason you can't wash them, just wipe away the first drop and use the second. But don't put too much pressure on the site or squeeze it – that may throw off your reading.
The rationale for wiping away the first drop of blood is that the alcohol in the prep pad, and consequently on the fingertip, may alter values. However, this rationale is controversial and techniques vary among nurses and facilities. Additionally, not all patients are able to produce a second drop of blood.
Environmental factors such as temperature can alter glucose meter readings. Modern glucose meters have built-in temperature sensors that will auto-correct measurements [1]. However, the temperature between the meter and the strip can differ leading to erroneous readings.
Avoid sugars and refined carbs
Don't eat high-sugar foods or simple carbs (including refined grains) the morning of your glucose screening. The body breaks these foods down quickly, leading to a spike in blood sugar levels. That means avoiding breakfast favorites like: Orange juice and other fruit juices.
Prick your finger with the lancing device at the sides of the finger as there are less nerve ending here than at the tips or the 'pads'. Recommended finger: the World Health Organisation recommends the middle or ring fingers are used for blood glucose tests (second and third fingers).
Excessive milking or squeezing of the puncture site can result in an unsatisfactory specimen because of hemolysis breaking down the blood cells to be analyzed or mixing tissue fluids in the specimen, which can dilute the blood.
Although you want to get the best results for each skin prick, when you're new to blood sugar testing it can be confusing to watch those results change throughout the day. “It's helpful to understand that blood sugar changes minute by minute,” says certified diabetes educator Karen A.
Make sure the hands are washed with soap and water and allowed to dry, or apply an alcohol-based sanitizer and leave it on for 30 seconds before lancing the finger. Water may lead to dilution of the blood, or the chemicals in the testing solution may solubilize too early, making the result invalid.
Doctors suggest that a normal fasting blood sugar range is between 70–100 mg/dL (3.9–5.6 mmol/L). If your fasting blood sugar is consistently over 126 mg/dL (7 mmol/L), your doctor will diagnose diabetes. You can reduce your risk of high fasting blood sugar by eating your dinner earlier the night before.
Blood sugar testing at home
In most cases, doctors ask people to measure fasting blood sugar immediately upon waking and before they have anything to eat or drink. It may also be appropriate to test blood sugar before eating or 2 hours after a meal, which is when blood sugar returns to normal levels.
Keep your glucose meter and test strips at room temperature. Wash and dry your hands and the testing site thoroughly with soap and water before pricking your skin. Don't use hand sanitizer before testing. If using alcohol wipes, let the site completely dry prior to pricking.
Target blood sugar levels differ for everyone, but generally speaking: if you monitor yourself at home – a normal target is 4-7mmol/l before eating and under 8.5-9mmol/l two hours after a meal. if you're tested every few months – a normal target is below 48mmol/mol (or 6.5% on the older measurement scale)
Skipping breakfast—going without that morning meal can increase blood sugar after both lunch and dinner. Time of day—blood sugar can be harder to control the later it gets. Dawn phenomenon—people have a surge in hormones early in the morning whether they have diabetes or not.
Drinking plenty of water helps your kidneys flush out excess sugar. One study found that people who drink more water lower their risk for developing high blood sugar levels. And remember, water is the best. Sugary drinks elevate blood sugar by raising it even more.
Excessive massaging or squeezing of the puncture site should be avoided in order to prevent hemolysis, contamination of the blood with interstitial and intracellular fluid, and obstruction of blood flow.
Apply slight pressure to start blood flow. Blot the first drop of blood on a gauze pad and discard pad in appropriate biohazard container. Apply a sterile adhesive bandage over the puncture site. Put on powder-free gloves.
The thumb has a pulse and is likely to bleed excessively. The index finger can be calloused or sensitive and the little finger does not have enough tissue to prevent hitting the bone with the lancet.
Drinking water before a fasting blood sugar test can actually decrease blood sugar levels, or at least prevent levels from getting too high. Water allows more glucose to be flushed out of the blood. When you're dehydrated, it means your overall blood volume is lower than normal, but your sugars will be the same.
Lab staff will note the time you finish drinking the glucose solution. DO NOT eat or drink anything except plain water after finishing the beverage. (No mints, cough drops or chewing gum. No smoking is allowed.)
Urine glucose may be falsely decreased by refrigerated urine, large amounts of ascorbic acid, tetracycline (due to ascorbic acid in the formulation), formaldehyde (metabolite of methenamine, used as a urinary antiseptic), low urine pH, and increased urine salt concentrations (paper test strip).