Making the Diagnosis
To diagnose diabetes, doctors will take a medical history (ask you about symptoms) and ask for blood and urine samples. Finding protein and sugar in the urine are signs of type 2 diabetes. Increased glucose and triglyceride (a type of lipid or fat) levels in the blood are also common findings. In most cases, blood glucose levels are checked after a person has been fasting for 8 hours.
If the fasting blood glucose level is 7.0 mmol/L (126 mg/dL) or higher, a diagnosis of diabetes is made. If the fasting blood glucose level is between 5.5 mmol/L and 6.9 mmol/L (100 mg/dL and 125 mg/dL), the person has impaired fasting glucose and may later develop diabetes.
Diabetes is also diagnosed if a blood glucose level taken anytime of the day without regards to meals is 200 mg/dL (11.1 mmol/L) or higher plus you have symptoms characteristic of diabetes (e.g., increase thirst, increase urination, unexplained weight loss). A doctor may also examine the eyes for signs of damage to the blood vessels of the retina (back of the eye).