Type 1 diabetes usually develops due to an autoimmune disorder. This is when the body’s immune system behaves inappropriately and starts seeing one of its own tissues as foreign. In the case of type 1 diabetes, the islet cells of the pancreas that produce insulin are seen as the “enemy” by mistake. The body then creates antibodies to fight the “foreign” tissue and destroys the islet cells’ ability to produce insulin.   The lack of sufficient insulin thereby results in diabetes. It is unknown why this autoimmune diabetes develops. Most often it is a genetic tendency. Sometimes it follows a viral infection such as mumps, rubella, cytomegalovirus, measles, influenza, encephalitis, polio, or Epstein-Barr virus. Certain people are more genetically prone to this happening although why this occurs is not know.  Thus, two people may be infected with the same virus and only one of them who is genetically prone will go on to develop diabetes. Other less common (very rare) causes of type 1 diabetes include injury to the pancreas from toxins, trauma, or after the surgical removal of the majority (or all) of the pancreas.

The major cause of type 2 diabetes is insulin resistance. Normally, the insulin secreted from the pancreas is taken by the fat and muscle cells to produce energy. But in a diabetic person this does not happen, and in turn the insulin levels in the body as well as the sugar levels in the blood keep on increasing. People who are overweight have a higher risk of this as excess fat usually interferes with the body’s ability to use insulin.

If someone in your family, especially a close relative like parents or siblings, has type 2 diabetes, your chances of getting the disease are relatively high.

Some other factors that may enhance the diabetic condition in the body are:

• Increased hepatic glucose production in the body at odd times
• Impaired function of the beta cells present in the pancreas
• Cancer patients who have received Hematopoeitic Cell Transplantation
• Age more than 45 years
• Ethnicity: Studies have shown that African–American, Native-American and Hispanic-American communities show a higher number of diabetes cases than other ethnic communities
• High blood pressure
• History of gestational diabetes
• Low physical activity
• Obesity
• Triglyceride cholesterol level of more than 250mg/Dl
• Previous diagnosis of impaired glucose tolerance