Hungery,thristy. Increased thirst and frequent urination. Extreme hunger. Weight loss. Fatigue. Irritability or unusual behavior. Blurred vision. Yeast infection in girls. Those the tests done after that to confirm it. Random blood sugar test. Glycated hemoglobin (a1c) test. Fasting blood sugar test. Autoantibodies that are common in type 1 diabetes. The presence of ketons in the urine.