High blood levels of glucose can cause several problems, including:
- Blurry vision
- Excessive thirst
- Fatigue
- Frequent urination
- Hunger
- Weight loss
However, because type 2 diabetes develops slowly, some people with high blood sugar experience no symptoms at all.
Symptoms of type 1 diabetes:
- Fatigue
- Increased thirst
- Increased urination
- Nausea
- Vomiting
- Weight loss in spite of increased appetite
Patients with type 1 diabetes usually develop symptoms over a short period of time. The condition is often diagnosed in an emergency setting.
Symptoms of type 2 diabetes:
- Blurred vision
- Fatigue
- Increased appetite
- Increased thirst
- Increased urination
A urine analysis may be used to look for glucose and ketones from the breakdown of fat. However, a urine test alone does not diagnose diabetes.
The following blood glucose tests are used to diagnose diabetes:
- Fasting blood glucose level -- diabetes is diagnosed if higher than 126 mg/dL on two occasions. Levels between 100 and 126 mg/dL are referred to as impaired fasting glucose or pre-diabetes. These levels are considered to be risk factors for type 2 diabetes and its complications.
- Oral glucose tolerance test -- diabetes is diagnosed if glucose level is higher than 200 mg/dL after 2 hours. (This test is used more for type 2 diabetes.)
- Random (non-fasting) blood glucose level -- diabetes is suspected if higher than 200 mg/dL and accompanied by the classic diabetes symptoms of increased thirst, urination, and fatigue. (This test must be confirmed with a fasting blood glucose test.)
You need your hemoglobin A1c (HbA1c) level checked every 3 - 6 months. The HbA1c is a measure of average blood glucose during the previous 2 - 3 months. It is a very helpful way to determine how well treatment is working.