A blood glucose test measures the glucose levels in your blood. Glucose is a type of sugar. It is your body’s main source of energy. A hormone called insulin helps move glucose from your bloodstream into your cells. Too much or too little glucose in the blood can be a sign of a serious medical condition. High blood glucose levels (hyperglycemia) may be a sign of diabetes, a disorder that can cause heart disease, blindness, kidney failure and other complications. Low blood glucose levels (hypoglycemia) can also lead to major health problems, including brain damage, if not treated.

Other names: blood sugar, self-monitoring of blood glucose (SMBG), fasting plasma glucose (FPG), fasting blood sugar (FBS), fasting blood glucose (FBG), glucose challenge test, oral glucose tolerance test (OGTT)

What is it used for?

A blood glucose test is used to find out if your blood sugar levels are in the healthy range. It is often used to help diagnose and monitor diabetes.

Why do I need a blood glucose test?

Your health care provider may order a blood glucose test if you have symptoms of high glucose levels (hyperglycemia) or low glucose levels (hypoglycemia).

Symptoms of high blood glucose levels include:

• Increased thirst
• More frequent urination
• Blurred vision
• Fatigue
• Wounds that are slow to heal

Symptoms of low blood glucose levels include:

• Anxiety
• Sweating
• Trembling
• Hunger
• Confusion

You may also need a blood glucose test if you have certain risk factors for diabetes. These include:

• Being overweight
• Lack of exercise
• Family member with diabetes
• High blood pressure
• Heart disease