Diabetes is a disease where the body does not properly process blood sugar (glucose) due to a lack of insulin or the body's inability to use insulin effectively. There are two main types of diabetes - type 1 where the body does not produce insulin and type 2 where the body does not properly use the insulin it produces. Signs of low blood sugar include hunger, sweating, weakness and signs of high blood sugar include increased thirst, frequent urination, and blurred vision.