Diabetes is diagnosed with the following blood tests: * Fasting blood glucose level -- diabetes is diagnosed if it is higher than 126 mg/dL two times * Random (nonfasting) blood glucose level -- you may have diabetes if it is higher than 200 mg/dL, and you have symptoms such as increased thirst, urination, and fatigue (this must be confirmed with a fasting test) * Oral glucose tolerance test -- diabetes is diagnosed if the glucose level is higher than 200 mg/dL after 2 hours * Hemoglobin A1c test * Normal: Less than 5.7% * Pre-diabetes: Between 5.7% and 6.4% * Diabetes: 6.5% or higher
The following tests or exams will help you and your doctor monitor your diabetes and prevent problems caused by diabetes: * Check the skin and bones on your feet and legs. * Check to see if your feet are getting numb. * Have your blood pressure checked at least every year (blood pressure goal should be 130/80 mm/Hg or lower). * Have your hemoglobin A1c test (HbA1c) done every 6 months if your diabetes is well controlled; otherwise, every 3 months. * Have your cholesterol and triglyceride levels checked yearly (aim for LDL cholesterol levels below 70-100 mg/dL). * Get yearly tests to make sure your kidneys are working well (microalbuminuria and serum creatinine). * Visit your eye doctor at least once a year, or more often if you have signs of diabetic eye disease. * See the dentist every 6 months for a thorough dental cleaning and exam. Make sure your dentist and hygienist know that you have diabetes.
* Glycated hemoglobin (A1C) test. This blood test indicates your average blood sugar level for the past two to three months. It works by measuring the percentage of blood sugar attached to hemoglobin, the oxygen-carrying protein in red blood cells. The higher your blood sugar levels, the more hemoglobin you'll have with sugar attached. An A1C level of 6.5 percent or higher on two separate tests indicates you have diabetes. A result between 5.7 and 6.4 percent is considered prediabetes, which indicates a high risk of developing diabetes.
If the A1C test isn't available, or if you have certain conditions that can make the A1C test inaccurate — such as if you're pregnant or have an uncommon form of hemoglobin (known as a hemoglobin variant) — your doctor may use the following tests to diagnose diabetes: * Random blood sugar test. A blood sample will be taken at a random time. Blood sugar values are expressed in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). Regardless of when you last ate, a random blood sugar level of 200 mg/dL (11.1 mmol/L) or higher suggests diabetes, especially when coupled with any of the signs and symptoms of diabetes, such as frequent urination and extreme thirst. A level between 140 mg/dL (7.8 mmol/L) and 199 mg/dL (11.0 mmol/L) is considered prediabetes, which puts you at greater risk of developing diabetes. * Fasting blood sugar test. A blood sample will be taken after an overnight fast. A fasting blood sugar level less than 100 mg/dL (5.6 mmol/L) is normal. A fasting blood sugar level from 100 to 125 mg/dL (5.6 to 6.9 mmol/L) is considered prediabetes. If it's 126 mg/dL (7 mmol/L) or higher on two separate tests, you have diabetes. A level from 100 mg/dL (5.6 mmol/L) to 125 mg/dL (6.9 mmol/L) is considered prediabetes.
If you're diagnosed with diabetes, your doctor will also run blood tests to check for autoantibodies that are common in type 1 diabetes. These tests help your doctor distinguish between type 1 and type 2 diabetes. The presence of ketones - byproducts from the breakdown of fat — in your urine also suggests type 1 diabetes, rather than type 2.
After the diagnosis
Once you've been diagnosed with type 1 diabetes, you'll regularly visit your doctor to ensure good diabetes management. During these visits, the doctor will check your A1C levels. Your target A1C goal may vary