Metabolic health
Glucose (fasting blood sugar)
Fasting plasma glucose, FPG, blood sugar
Included in Baseline and Complete.
Compare membershipsYour blood sugar at the moment of your draw.
Glucose is the main sugar your body uses for energy. Measured after fasting, it shows how well your body keeps blood sugar steady between meals, and it's one of the main results used to assess diabetes risk.
Fasting makes your result easier to compare.
Your blood sugar rises after you eat, then insulin brings it back down. Diabetes Canada defines fasting as no calories for at least eight hours, so a fasting result reflects your baseline and is easier to compare over time.
Because glucose changes from hour to hour, one result is a snapshot. Diabetes Canada's guidelines use fasting glucose and HbA1c to define prediabetes and diabetes, and a result in the diabetes range is repeated on another day before it's confirmed.
Glucose shows the moment. HbA1c shows the trend.
Questions
What can affect my glucose result?
Eating or drinking anything other than water before the draw can raise it. Stress from serious illness, injury, or surgery can push it up, and some medicines, including steroids, some blood pressure drugs, and statins, can affect it. Let your clinician know what you take.
What does a higher fasting glucose mean?
A higher fasting glucose may point to prediabetes or diabetes, especially if your HbA1c is also raised. Less often, it relates to other hormone conditions or medicines. Your result is read with your HbA1c, health history, and symptoms, and repeat testing is common.
What if my glucose is low?
Low fasting glucose is uncommon in people without diabetes. Some medicines, heavy alcohol use, and some liver, kidney, or hormone conditions can lower it. If you've noticed symptoms like shakiness or sweating, mention them to your clinician.