Monitoring Blood Glucose

Blood sugar is also called blood glucose.

Why do I Need to Check My Blood Glucose?

  • To keep you safe
  • To help you and your health care team manage your blood glucose levels
  • To help you change your insulin doses
  • To help you manage your daily activities, like school, work, exercise, and the food you eat

Always Check at these Times:

  • Before breakfast, lunch, and dinner
  • Before bed
  • When you have signs of low blood glucose (see ‘Low Blood Glucose’ on page 46)
  • Each time you get in a car to drive

Sometimes You will Need to Check at these Times:

  • Middle of the night
  • Before, during, and after exercise

Check More Often:

  • When you are sick
  • Check blood glucose between 2 a.m. and 4 a.m. if there is a chance your blood glucose may be low.
  • Check for 2 to 3 nights after changing your Lantus® insulin dose.
  • When you have an unusual amount of exercise late in the day.
  • When you are sick.
  • When your blood glucose is low before bed.

What Supplies do I Need?

Blood glucose meter
Blood Glucose Meter

blood glucose test strips
Blood Glucose Test strips

lancet device
Lancet Device


Container for used lancets (sharps container or a container made of thick plastic, like a detergent bottle or bleach bottle)

How do I Check My Blood Glucose?

  1. Wash your hands.
  2. Put the lancet in the lancet device.
  3. Put the test strip into the blood glucose meter.
  4. Stick the finger on its side near the top of the finger (Picture 1).
  5. Squeeze the finger so a drop of blood comes up on the skin.
  6. Touch the blood sample to the test strip.
  7. Read the blood glucose number on meter.

poking side of finger with lancet


Picture 1: Poke the side of the finger with the lancet

Important Tips

  • Use a new lancet every time you check your blood glucose.
  • Throw away the lancet right after it is used. Put it in the container.
  • When the container is almost full, tape the lid on tightly.
  • Write “SHARPS” on the front, and put it in the trash.

What Number should My Blood Glucose be?

Blood glucose is measured in mg/dl. The normal range for blood glucose for people without diabetes is 70 to 120 mg/dl.

The Diabetes Center has guidelines for blood glucose readings. This is called a target range. There may be times when your healthcare provider gives you a different target range, like for bedtime, with exercise, or after eating.

Nationwide Children’s Hospital Diabetes Center Target Blood Glucose Ranges

Age Blood Glucose mg/dl
0 to 5 years old 100 to 180
6 to 9 years old 80 to 140
10 years old or more 70 to 120

The goal is to keep the blood glucose within the target range most of the time.

What Should I do After I Check my Blood Glucose?

Write the blood glucose number in a log book or on a log sheet (page 18), and:

  • Include all of your blood glucose numbers.
  • Write a comment if there is a reason the blood glucose is above or below target.


log to manage diabetes

Important Tips

  • Take your blood glucose meter with you when you are away from home.
  • Know your blood glucose numbers when you call the clinic or the doctor.
  • Bring your blood glucose meter and blood glucose records to all your appointments.
  • Bring a list of any questions that you may have.

How do I Take Care of My Blood Glucose Meter?

  • Set the date and time when you get a new meter.
  • Make sure the date and time are right each time you use your meter.
  • Use the control solution as needed. This will let you know the meter and test strips are working right. Use it:
    • When you get a new meter.
    • When you get new test strips.
    • When you think that the meter is not giving you the right blood glucose number.
  • Keep the meter and test strips out of very hot or very cold temperatures. This can cause blood glucose numbers to be wrong.
  • Keep meter and test strips in a case, away from sunlight.
  • Keep test strips in the container they come in. Keep the lid closed.
  • Keep extra batteries with your meter.
  • There is a phone number on the back of each blood glucose meter. Call that number if your meter is not working or you have questions about how to use your meter.

What is Hemoglobin A1C?

Hemoglobin A1C is a lab test. It indicates an average blood glucose reading for the last 90 days. It is done when you find out you have diabetes, and every 3 months after that at clinic visits. A person without diabetes has a Hemoglobin A1C of less than 5.6%.

Target Hgb A1C is 7.5% for all children and adults with diabetes.

The chart below shows the Hemoglobin A1C result compared with the blood glucose number.

A1c result compared to the blood glucose number

Download the Diabetes Blood Glucose/Insulin Record 

Back to the Managing Your Diabetes Resource Book Table of Contents