Testing your blood sugar at home takes about a minute using a small device called a glucose meter (or glucometer) and a drop of blood from your fingertip. Most people with diabetes or prediabetes check this way, though continuous glucose monitors offer a hands-free alternative. Here’s everything you need to get started and get accurate results.
What You Need
A basic home testing kit includes a glucose meter, test strips designed for that specific meter, a lancing device (a spring-loaded pen that holds a tiny needle), and individually wrapped lancets. You can buy these at any pharmacy without a prescription. Test strips are the ongoing cost, so it’s worth comparing strip prices across brands before choosing a meter.
Keep a few extras on hand: soap and water for washing your hands before each test, tissues or gauze to press on your finger afterward, and a sturdy container for used lancets. A heavy-duty plastic bottle with a screw-on lid, like a laundry detergent container, works if you don’t have a dedicated sharps disposal box. You’ll also want a log, whether that’s a notebook, a spreadsheet, or an app, to record your readings over time.
Step-by-Step Testing Process
Wash your hands with warm soap and water and dry them completely. Residue from food, lotion, or hand sanitizer can throw off your reading. Warm water also helps increase blood flow to your fingertips, which makes the next step easier.
Shake or massage your hand gently to push blood toward your fingertip. Insert a fresh lancet into the lancing device and adjust the depth setting. If you have thicker skin, you may need a deeper setting, but start shallow and increase only if you aren’t getting enough blood. Prick the side of your fingertip rather than the pad. The sides have fewer nerve endings, so it hurts less.
Insert a test strip into your meter. Squeeze gently from the base of your finger until a small drop of blood forms, then touch it to the edge of the test strip. The meter will display your blood sugar level within a few seconds. Record the number along with the date, time, and any notes about what you ate, whether you exercised, or anything else that might have affected the result. Dispose of the lancet in your sharps container, never loose in the trash.
When and How Often to Test
The most informative times to check are when you first wake up (before eating or drinking anything), right before meals, and two hours after the start of a meal. A bedtime check can also be useful. Your doctor may recommend a different schedule depending on your medications and how well-controlled your blood sugar is, but those four time points give the clearest picture of how your body handles glucose throughout the day.
Fasting readings (first thing in the morning) tell you what your baseline blood sugar looks like. Post-meal readings reveal how your body responds to specific foods, which is especially helpful if you’re adjusting your diet.
What the Numbers Mean
For most adults with diabetes, the general targets are 80 to 130 mg/dL before a meal and less than 180 mg/dL two hours after the start of a meal. These are the standard ranges recommended by the American Diabetes Association, though your personal targets may differ based on your age, health conditions, and treatment plan.
A single reading outside these ranges isn’t cause for alarm. Blood sugar fluctuates throughout the day in response to food, activity, stress, sleep, and illness. What matters most is the pattern over days and weeks, which is why consistent logging is so valuable. Bring your log to medical appointments so your provider can spot trends and adjust your care if needed.
Testing on Sites Other Than Your Fingertip
Some meters allow testing on the forearm, thigh, or palm. If pricking your fingertips has become painful from frequent testing, these alternatives may appeal to you, but they come with trade-offs. Forearm and thigh readings are only reliable during steady-state conditions, meaning before meals when your blood sugar isn’t changing quickly. After eating or exercising, blood sugar in the forearm and thigh lags behind your actual level, which can give you a misleadingly low or high number.
The palm is a better alternative. Studies show palm readings closely match fingertip readings at all times, including after meals and exercise. If you switch sites, test on both your fingertip and the alternate site a few times to compare and make sure the results are consistent for you.
Getting Accurate Readings
Several things can quietly skew your results. The most common culprit is dirty hands. Even a trace of sugar from fruit or juice on your fingertip can produce a falsely high reading. Always wash with soap and water first. Hand sanitizer or alcohol pads work in a pinch, but let your skin dry completely before testing.
Heat and humidity affect test strip chemistry. The enzyme on the strip starts losing accuracy when temperatures climb above about 99°F (37°C), and high humidity compounds the problem. Store your strips in their original sealed container at room temperature, ideally below 77°F (25°C) and under 70% humidity. Don’t leave your kit in a hot car, a steamy bathroom, or direct sunlight. Strips that have been exposed to extreme conditions, even briefly, can give consistently lower readings without any obvious sign of damage.
Check the expiration date on your test strips. Expired strips are unreliable. If your meter uses a control solution (a liquid with a known glucose concentration), run a quality check whenever you open a new box of strips or if your readings suddenly seem off.
Continuous Glucose Monitors
A continuous glucose monitor, or CGM, is a small sensor you wear on the back of your arm or your abdomen. A thin filament sits just beneath the skin and measures glucose in the fluid between your cells, sending updated readings to your phone or a separate receiver every few minutes.
Applying the sensor takes about a minute. You clean the skin with soap and water (skip the lotion), press the applicator against your skin, and click. The insertion feels like a quick pinch, similar to a fingerstick, and most people don’t notice it once it’s in place. Sensors typically last 10 to 14 days before you swap in a new one.
The advantage of a CGM is the continuous data stream. Instead of four or five snapshots a day, you see a real-time graph showing how your blood sugar rises and falls in response to meals, exercise, stress, and sleep. Many CGMs also alert you when your glucose is trending too high or too low, which is especially useful overnight or if you have trouble recognizing low blood sugar symptoms. The trade-off is cost. CGMs are more expensive than meters and strips, and insurance coverage varies.
Safe Disposal of Lancets
Used lancets are considered sharps, the same category as needles and syringes. Tossing them loose in the trash puts household members, children, and waste workers at risk of puncture injuries. Place each used lancet immediately into a puncture-resistant container with a secure lid. FDA-cleared sharps containers are sold at pharmacies and online, but a thick plastic household bottle with a screw cap works just as well.
When the container is about three-quarters full, seal it and check your local guidelines for disposal. Many pharmacies, hospitals, and fire stations accept filled sharps containers. Some communities offer mail-back programs. Never put loose sharps in recycling bins or flush them down the toilet.