How to Test Your Blood Sugar With Diabetes
When Should I Test My Blood Sugar?
Blood sugar testing is usually recommended before meals, after meals, and at bedtime. Daily blood glucose checks are especially important for people on insulin or the sulfonylureas class of antidiabetes drugs.
Frequency and timing of blood glucose measurements should be individualized. Your health care provider will tell you when and how often you should check your blood glucose.
Note: Acute or chronic illnesses or changes in medications may affect your glucose level. You may need to test your blood glucose more frequently when you are ill.
Conditions That Affect Your Blood Sugar
Certain conditions may interfere with an accurate reading of blood sugar, and include:
- Anemia
- Gout
- High air temperature
- Humidity
- Altitude
If you are consistently seeing abnormal results, recalibrate your meter and check the strips.
The chart below gives you an idea of where your blood glucose level should be throughout the day. Your ideal blood glucose range may be different from another person's and will change throughout the day.
| Time of Test | Ideal for Adults With Diabetes |
| Before meals | 90-130 mg/dL |
| Before bedtime snack | Less than 180 mg/dL |
| *Source: American Diabetes Association, 2005 | |
Home Blood Glucose Monitoring and HbA1c
Monitoring your HbA1c level is also important for diabetes control. Many home glucose monitors have the capacity to display an average blood glucose reading, which correlates with the HbA1c.
Learn more about HbA1c.
| Average Blood Glucose Level (mg/dL) | HbA1c (%) |
| 124mg/ dL | 6.3 |
| 147mg/ dL | 7 |
| 180mg/ dL | 8 |
| 214mg/ dL | 9 |
| 247mg/ dL | 10 |
| 280mg/ dL | 11 |
When Should I Call My Doctor About my Blood Sugar?
In most cases, a fasting blood sugar level more than 180 mg/dL is too high and a blood glucose level less than 70 mg/dL is too low. If you are having symptoms of low blood sugar, or if your blood glucose is less than 70 mg/dL and you have more than one unexplained low blood glucose reaction a week, call your health care provider.
If you are having symptoms of high blood sugar, or if your blood glucose is greater than 180 mg/dL for more than a week, or if you have two consecutive readings greater than 300 mg/dL, call your health care provider. In most cases, your doctor will suggest changes in your diabetes management plan.
How Do I Record My Blood Sugar Test Results?
Keep good records of any blood, urine, or ketone tests you do. Your records can help alert you to any problems. Also, these test records help your health care provider make any needed changes in your meal plan, medicine, or exercise program. Bring these records with you every time you visit your health care provider.
Reviewed by physicians in the Department of Endocrinology at The Cleveland Clinic.
