There are two types of Diabetes. Type I and Type II Diabetes.
Type I Diabetes:
Unexplained weight loss. You may lose weight even though your dietary plan remain same.
Nausea and vomiting. When your body Fat starts burning, it results increase in Ketone Bodies in the blood, which may end up in a life threatening condition known as Diabetic Ketoacidosis.
Type II Diabetes:
Symptoms often develop slowly. In fact the disease may remain for years together without any symptoms.
Look for - Increased thirst and frequent urination. Excess sugar in the blood causes fluid to be driven out from tissues, resulting increase in thirst and urination.
Weight loss - Despite eating more than usual, one may loose weight. Without the ability to metabolize glucose, the body uses alternative fuels stored in muscle and fat. Calories are lost as excess glucose released in the urine.
Slow-healing sores or frequent infections - Type 2 diabetes affects the healing process of any kind of wounds.