Symptoms may develop suddenly. Or they may develop gradually over days to weeks. Symptoms vary widely from person to person. Common symptoms include increased urination, increased thirst and dry mouth, increased appetite or loss of appetite, unexpected weight loss, blurred vision, tiredness, or a fruity odor on your breath.

If diabetes is not treated, you could develop a life-threatening chemical imbalance called ketoacidosis and possibly go into a coma.

Your doctor will ask about your medical history and your symptoms and examine you. He or she will test the level of sugar in your blood. Two blood tests may be done to diagnose diabetes.

The fasting plasma glucose (FPG) test is easier, faster, and less expensive to do. A sample of your blood is tested in the morning before you have eaten anything. If this test shows you have a fasting blood sugar of 126 or more, you may be diabetic. Two FBG tests are recommended for a diagnosis.

For the oral glucose tolerance test (OGTT), a sample of your blood is taken and tested when you have not eaten anything since the night before. Then you drink a sugar drink and your blood is tested again 2 hours later. If after 2 hours your blood sugar level is 200 or higher, you are diabetic.