Blood Glucose Monitoring, Adult

• Know when to adjust your diabetes management plan with your health care provider.
• See how food, exercise, illness, and medicines affect your blood glucose.
• Know what your blood glucose is at any time.

• 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 once.
• A device that holds the lancet (lancing device).
• A journal or logbook to write down your results.

How to check your blood glucose

Checking your blood glucose

1. Wash your hands with soap and water for at least 20 seconds.
2. Prick the side of your finger with the lancet. Do not prick the tip of your finger. Do not use the same finger more than once.
3. Gently rub the finger until a small drop of blood appears.
4. Follow the instructions that came with the meter about how to insert the test strip, apply blood to the strip, and use the meter.
5. Write down your result and any notes.

Using alternative sites

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

Alternative sites may not be as accurate as your fingers. The result you get may also be delayed.

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

General tips and recommendations

Blood glucose log

• Write down the result each time you check your blood glucose. Note anything that may be affecting your blood glucose. This can help you and your provider:
  • Look for patterns over time.
  • Adjust your management plan as needed.
• Check if your meter has an app or lets you download your records to a computer. Most meters keep a record of glucose readings in the meter.

If you have type 1 diabetes:

• You may need to check your blood glucose 4 or more times a day. Check your blood glucose as often as told by your provider. This may include:
  • Before each meal and snack.
  • Two hours after a meal.
  • Before bedtime.
  • If you have symptoms of hypoglycemia.
  • After treating your hypoglycemia.
  • Before doing things that have a risk of injury, such as driving or using machinery.
  • Before and after exercise.
  • Between 2:00 a.m. and 3:00 a.m., as told.
• You may need to check your blood glucose more often, such as up to 6–10 times a 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:

• You may need to check your blood glucose 2 or more times a day. Check your blood glucose as often as told by your provider. This may include:
  • Before and after exercise.
  • Before doing things that have a risk of injury, such as 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. Follow the instructions that came with your meter.
• If you have questions or need help, all blood glucose meters have a 24-hour hotline phone number that you can call. Also contact your provider with any questions or concerns.

Where to find more information

• The American Diabetes Association: diabetes.org
• The Association of Diabetes Care & Education Specialists: 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 are not getting better.
• You have any of these 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 trouble breathing.
• You have moderate to high ketone levels in your pee (urine).

• Do not wait to see if the symptoms will go away.
• Do not drive yourself to the hospital.