What is the cause, effect and symptoms of diabetes?

Too much sugar!: Diabetes mellitus is a disorder of high blood sugars caused by either deficiency of Insulin (type 1) or a partial deficiency of Insulin caused by the body not responding to Insulin (type 2). High glucose levels can cause short-term symptoms (thirst, frequent urination), but more worrisome are the long-term complications of high glucose levels, such as blindness, kidney disease, and heart disease.