Everyone with diabetes should have their blood glucose (glucose) levels tested regularly. Knowing the results helps to adjust treatment as needed to manage the disease.
Testing your blood sugar regularly also helps avoid long-term health problems from diabetes. Studies have shown that for people with type 1 or type 2 diabetes, keeping your blood glucose and glycosylated hemoglobin levels stable at target values reduces the likelihood of complications.
Ways to test your blood glucose
Traditional home glucose monitoring method
Puncture your finger with a blood collection needle (a small, sharp needle), put a drop of blood on a test strip, and then place the test strip into a glucose meter that displays your blood glucose level.
There are many types of blood glucose meters based on function, portability, speed, size, cost, and readability (with larger displays or audio instructions if you have vision problems). Blood glucose meters can display test results in 15 seconds or less and store the result information for later use.
Some meters can also calculate the average blood glucose level over a period of time. Some meters also have software packages that take information from the meter and display past test results in graphs and charts. Patients can purchase blood glucose meters and test strips at their local pharmacy.
Glucose meters that test other parts of the body
Some devices can test the upper arm, forearm, thumb root, and thigh.
The results of these tests may not be the same as the blood glucose levels tested on the fingertips. Blood glucose levels at the fingertips change more quickly. This is especially true, for example, after a meal or after exercise.
Do not rely on test results from other parts of the body if you have symptoms of hypoglycemia.
An ambulatory blood glucose monitoring system
Some of these devices have an integrated insulin pump. Although not as accurate as fingertip glucose tests, they can help patients understand patterns and trends in blood glucose levels. Some physicians refer to them as “interstitial glucose measurement devices.
When to measure blood glucose?
When to measure blood glucose?
Everyone is different.
Everyone is different. Your doctor will tell you when and how often to check your blood glucose.
For patients who use insulin more than once a day or use an insulin pump, specialists may recommend testing blood glucose at least three times a day.
What factors can affect test results?
Glucose test results may be inaccurate if the patient has anemia or gout. If the weather is hot, humid, or at high altitude, the test results may also be affected. In addition, vitamin C can affect the test results.
If you consistently do not get the expected results, recalibrate your meter and check the test strips.
The chart below shows the ideal blood glucose range for most adults, except for pregnant women. Each person’s ideal range may be different from others and can change throughout the day, so check with your doctor for your personal blood glucose target range.
| Check time | ideal range for adults with diabetes |
| Before meals | 70 to 130 mg/dL |
| 1 to 2 hours after a meal | Less than 180 mg/dL |
| Source: American Diabetes Association, 2014 | |
Glucose and glycosylated hemoglobin testing at home
It is also important to test glycosylated hemoglobin levels. Many home glucose monitors can display average blood glucose readings, which correlate with glycosylated hemoglobin testing.
| Average blood glucose levels (mg/dL) | Glycosylated hemoglobin (%) |
| 6 | |
| 154 mg/dL | 7 |
| 183 mg/dL | 8 |
| 212 mg/dL | 9 |
| 240 mg/dL | 10 |
| 269 mg/dL | 11 |
| 298 mg/dL | 12 |
When should I consult my doctor?
Consult your doctor about your target blood glucose range. Also, work with your doctor to develop a plan on how to respond to a situation where your blood glucose reading is too high or too low and when you should contact your doctor. Know the symptoms of high or low blood glucose, and know what to do if these symptoms occur.
Understand how blood glucose changes over time
Keep a record of all test results. Most blood glucose monitors can also store past test results. A record of tests allows the patient to stay alert to trends to avoid any problems.
In addition, these test records can help the doctor make any necessary changes to the patient’s meal plan, medications, or exercise program. Carry these records with you every time you have a checkup.