Type 1 diabetes
Type 1 diabetes mostly occurs n childhood or adolescence. The reason is damage of insulin producing cells of the pancreas through genetic factors, virus infects and other not completely known impacts. There is no insulin production at all (absolute lack of insulin) so daily injections of insulin are necessary to survive. It is also important to take care about healthy nutrition and doing exercise.
Type 2 diabetes
Type 2 diabetes mostly occurs after the age of 40. Due to a changed lifestyle in industrial nations (overweight and lack of exercise) the manifestation of type 2 diabetes can be seen at much younger persons (adolescents). A genetic burden and overweight are the most important risk factors. Insulin which is produced in the body has decreased activity at the insulin receptors (insulin resistency). This leads to a higher production rate of insulin (hyperinsulinemia) which overburdens insulin producing beta cells causing prostration ahead of time (relative lack of insulin).
The manifestation of diabetes type 2 takes place after an long pre-diabetic phase. Very often it appears contemporarily with the so-called metabolic syndrome which is characterized through overweight, high blood fats, hypertension and insulin resistency.
This metabolic disease is caused by reduced effect of insulin during pregnancy. The risk is increased for woman older than 25 years of age and relatives of the first grade with diabetes. It is from utmost importance to keep blood glucose levels in a tight range to ensure normal development of the child. After the end of the pregnancy blood glucose levels will be in normal range again but there is an increased risk to develop diabetes type 2 later on.
As a late complication of serious diseases of the pancreas, disease of several glands (e.g. thyroid) or medication like cortisol secondary diabetes can be developed.