Monitoring blood sugars: Why, when, where and how

Why: Checking blood sugar is one of the most important tasks of managing type 1 diabetes.


Blood sugar levels guide decisions about treatment, such as when and how much insulin to give, and when a student needs a snack.

Communicating the results of routine and extra blood sugar checks from the school back to the parents is also important. If there is a pattern of blood sugars outside the target range for a few days, parents may need to adjust the student’s insulin dose.

When: Students will typically check blood sugar before meals (always) and before snacks (sometimes), before and/or after physical activity, and when they feel symptoms of low blood sugar or high blood sugar. A student’s Individual Care Plan will provide more details.

Where: Students should be able to check blood sugar wherever they are, especially if they have symptoms of low blood sugar.


It is not safe to send a student to a different location or leave them alone if they have a suspected low blood sugar.

If a student feels low, and you are unable to check blood sugar on the spot, treat as if the student is low.

How: Some students can check their blood sugar on their own. Others will need supervision, or someone to do it for them.

Here is a general guide to the steps involved in checking blood sugar. Because there are many different meters available, be sure to follow the manufacturer’s instructions for the student’s meter. Designated staff who provide support to a student with type 1 diabetes should be trained on the student’s meter.

  • Start with clean hands: Have the student wash with warm, soapy water or use an alcohol swab (not hand sanitizer).
  • Gather equipment: meter, test strips, lancet.
  • Prepare the meter:
    • Take a strip from the canister and close the canister.
    • Insert the strip in the meter, pushing firmly until the meter turns on.
    • There will be an indication (such as a flashing blood drop) when the meter is ready.
  • Poke the student’s finger (let the student choose which one).
    • Insert a new lancet, and pull back the arm of the lancing device until it clicks.
    • Place the lancing device firmly against the side of the student’s fingertip and press the button.
    • Squeeze the finger gently to obtain a small drop of blood.
  • Touch the strip to the blood drop (some test strips will pull in the required amount of blood) until there is a beep or other indication from the meter.
  • Wait about 5 seconds for the reading to appear. (Note: If blood sugar is below 4 mmol/L, treat accordingly)
  • Remove strip and lancet and dispose in sharps container.

Continuous Glucose Monitors (CGMs)

Some students use a Continuous Glucose Monitor (CGM) a device that automatically provides readings every few minutes, day and night. A sensor is inserted underneath the skin, where it measures “interstitial glucose”, or the glucose found in the fluid between cells. The sensor sends this information wirelessly to a monitor either continuously or when the sensor is scanned with a monitor.

The monitor may be on a student’s insulin pump, phone or it may be a separate device that the student keeps in a backpack, pocket or somewhere else nearby. Not all students who use a CGM will have an insulin pump.

A CGM does not replace traditional BG checking. If fingersticks are needed, details as to when will be in the Individual Care Plan.

If the CGM and meter results differ, the meter reading is considered the most reliable.

If a student uses a CGM, detailed instructions will be in the Individual Care Plan.

For more information:

Last updated: