There are two main types of diabetes, a chronic disease caused by the inability of the pancreas to produce or properly use insulin. With type I, or insulin-dependent diabetes, the pancreas makes almost no insulin, affecting about 10 percent of people with diabetes. With type II, or non-insulin-dependent diabetes, either the pancreas produces a reduced amount of insulin, the cells do not respond to the insulin, or both. Virtually everyone with type I diabetes must inject insulin to make up for the deficiency. Diet and regular physical activity can help manage type II diabetes.