Blood Glucose Monitoring, Adult

Monitoring your blood sugar (glucose) is an important part of managing your diabetes. Blood glucose monitoring involves checking your blood glucose as often as directed and keeping a log or record of your results over time.

• Help you and your health care provider adjust your diabetes management plan as needed, including your medicines or insulin.
• Help you understand how food, exercise, illnesses, and medicines affect your blood glucose.
• Let you know what your blood glucose is at any time. You can quickly find out if you have low blood glucose (hypoglycemia) or high blood glucose (hyperglycemia).

• Before meals (preprandial): 80–130 mg/dL (4.4–7.2 mmol/L).
• After meals (postprandial): below 180 mg/dL (10 mmol/L).
• A1C level: less than 7%.

Supplies needed:

• Blood glucose meter.
• Test strips for your meter. Each meter has its own strips. You must use the strips that came with your meter.
• A needle to prick your finger (lancet). Do not use a lancet more than one time.
• A device that holds the lancet (lancing device).
• A journal or log book to write down your results.

How to check your blood glucose

Checking your blood glucose

1. Wash your hands for at least 20 seconds with soap and water.
2. Prick the side of your finger (not the tip) with the lancet. Do not use the same finger consecutively.
3. Gently rub the finger until a small drop of blood appears.
4. Follow instructions that come with your meter for inserting the test strip, applying blood to the strip, and using your blood glucose meter.
5. Write down your result and any notes in your log.

Using alternative sites

Some meters allow you to use areas of your body other than your finger (alternative sites) to test your blood. The most common alternative sites are the forearm, the thigh, and the palm of your hand.

Alternative sites may not be as accurate as the fingers because blood flow is slower in those areas. This means that the result you get may be delayed, and it may be different from the result that you would get from your finger.

• You think you have hypoglycemia.
• You sometimes do not know that your blood glucose is getting low (hypoglycemia unawareness).

General tips and recommendations

Blood glucose log

• Every time you check your blood glucose, write down your result. Also write down any notes about things that may be affecting your blood glucose, such as your diet and exercise for the day. This information can help you and your health care provider:
  • Look for patterns in your blood glucose over time.
  • Adjust your diabetes management plan as needed.
• Check if your meter allows you to download your records to a computer or if there is an app for the meter. Most glucose meters store a record of glucose readings in the meter.

If you have type 1 diabetes:

• Check your blood glucose 4 or more times a day if you are on intensive insulin therapy with multiple daily injections (MDI) or if you are using an insulin pump. Check your blood glucose:
  • Before every meal and snack.
  • Before bedtime.
• Also check your blood glucose:
  • If you have symptoms of hypoglycemia.
  • After treating low blood glucose.
  • Before doing activities that create a risk for injury, like driving or using machinery.
  • Before and after exercise.
  • Two hours after a meal.
  • Occasionally between 2:00 a.m. and 3:00 a.m., as directed.
• You may need to check your blood glucose more often, 6–10 times per day, if:
  • You have diabetes that is not well controlled.
  • You are ill.
  • You have a history of severe hypoglycemia.
  • You have hypoglycemia unawareness.

If you have type 2 diabetes:

• Check your blood glucose 2 or more times a day if you take insulin or other diabetes medicines.
• Check your blood glucose 4 or more times a day if you are on intensive insulin therapy. Occasionally, you may also need to check your glucose between 2:00 a.m. and 3:00 a.m., as directed.
• Also check your blood glucose:
  • Before and after exercise.
  • Before doing activities that create a risk for injury, like driving or using machinery.
• You may need to check your blood glucose more often if:
  • Your medicine is being adjusted.
  • Your diabetes is not well controlled.
  • You are ill.

General tips

• Make sure you always have your supplies with you.
• After you use a few boxes of test strips, adjust (calibrate) your blood glucose meter by following instructions that came with your meter.
• If you have questions or need help, all blood glucose meters have a 24-hour hotline phone number available that you can call. Also contact your health care provider with questions or concerns you may have.

Where to find more information

• The American Diabetes Association: www.diabetes.org
• The Association of Diabetes Care & Education Specialists: www.diabeteseducator.org

Contact a health care provider if:

• Your blood glucose is at or above 240 mg/dL (13.3 mmol/L) for 2 days in a row.
• You have been sick or have had a fever for 2 days or longer, and you are not getting better.
• You have any of the following problems for more than 6 hours:
  • You cannot eat or drink.
  • You have nausea or vomiting.
  • You have diarrhea.

Get help right away if:

• Your blood glucose is lower than 54 mg/dL (3 mmol/L).
• You become confused, or you have trouble thinking clearly.
• You have difficulty breathing.
• You have moderate or large ketone levels in your urine.

These symptoms may represent a serious problem that is an emergency. Do not wait to see if the symptoms will go away. Get medical help right away. Call your local emergency services (911 in the U.S.). Do not drive yourself to the hospital.

Summary

• Monitoring your blood glucose is an important part of managing your diabetes.
• Blood glucose monitoring involves checking your blood glucose as often as directed and keeping a log or record of your results over time.
• Your health care provider will set individualized treatment goals for you. Your goals will be based on your age, other medical conditions you have, and how you respond to diabetes treatment.
• Every time you check your blood glucose, write down your result. Also, write down any notes about things that may be affecting your blood glucose, such as your diet and exercise for the day.