What is Blood Glucose?

Blood glucose, commonly called blood sugar, is the main sugar found in your blood. It comes from the food you eat and is your body's primary source of energy. Insulin, a hormone produced by the pancreas, helps glucose enter your cells to be used for energy.

Why is it Important?

Blood glucose levels are a key indicator of how well your body processes sugar. Persistently high levels can lead to type 2 diabetes, heart disease, kidney damage, and nerve problems. Low levels can cause confusion, dizziness, and in severe cases, loss of consciousness.

Normal Ranges

Reference ranges are for fasting blood glucose (no food for at least 8 hours).

Group	Range	Unit
Normal (Fasting)	70 – 100	mg/dL
Prediabetes (Fasting)	100 – 125	mg/dL
Diabetes (Fasting)	≥ 126	mg/dL
Normal (Fasting)	3.9 – 5.6	mmol/L

What Do Abnormal Results Mean?

Low Glucose (Hypoglycemia)

Common causes include:

Diabetes medications (insulin, sulfonylureas)
Skipping meals or prolonged fasting
Excessive alcohol consumption
Adrenal or pituitary gland disorders
Liver disease

High Glucose (Hyperglycemia)

Common causes include:

Type 1 or type 2 diabetes
Prediabetes (insulin resistance)
Pancreatic disorders
Stress, illness, or infection
Certain medications (corticosteroids, diuretics)

When Should You Get Tested?

Fasting glucose is part of routine metabolic panels. Your doctor may order it if you have risk factors for diabetes (obesity, family history, sedentary lifestyle) or symptoms like frequent urination, excessive thirst, unexplained weight loss, or blurred vision.