Lab Values Used to Diagnose Diabetes

A glucose test measures the amount of sugar (glucose) in the blood. These tests can be used to diagnose or screen for diabetes or to monitor patients who have diabetes.
 
Glucose is a major source of energy for most cells of the body, and the major hormone regulating glucose concentration in the body is insulin.
 
People with type 1 diabetes require daily injections of insulin to control their disease. Injecting too much or too little insulin in your body can be dangerous because of the limited range of blood sugar levels that allow the brain to function normally.
 
These are the ranges that are used to diagnose diabetes:
 

Diagnosis	Fasting Blood Glucose	Casual Blood Glucose
No Diabetes	Less than 100 mg/dl	Less than 140 mg/dl
Pre-Diabetes	100-125 mg/dl	140-199 mg/dl
Diabetes	126 mg/dl or higher on two occasions	200 mg/dl or higher and symptoms