Type 1 diabetes is caused by an autoimmune reaction in which the body's immune system attacks insulin-producing β cells in the pancreas. As a result, the body reduces or stops producing insulin altogether. The causes of this disruptive process are not fully understood, but the likely explanation is that a combination of genetic susceptibility (granted by a large number of genes) and an external trigger (such as a viral infection) initiates an autoimmune response. Toxins or some dietary factors also have an impact on this process.
The disease can develop at any age, although type 1 diabetes is most common in children and young adults. Type 1 diabetes mellitus is one of the most common chronic diseases in childhood, although type 2 diabetes is also seen in older children, and it increases due to overweight and obesity in childhood.
People with type 1 diabetes need daily insulin injections to keep their glucose levels within appropriate limits. With proper daily insulin treatment, regular monitoring of blood glucose levels, sufficient awareness and support, such patients can live a normal life, avoid many complications associated with diabetes mellitus.
Following a structured self-management plan that includes insulin use, blood glucose monitoring, physical activity, and a healthy diet is especially difficult in early childhood as well as adolescence. In many countries, especially low-income families, access to insulin and self-care tools, including structured diabetes education, may be limited. This is most often fatal due to the accumulation of harmful substances known as "ketones" in the body (diabetic ketoacidosis, DKA).
Type 1 diabetes mellitus remains a problem even in countries where patients have established access to multiple daily injections or insulin pumps, glucose control, structured diabetes education, and skilled medical care. In addition to the acute complications of hypoglycemia (abnormally low blood glucose) and DKA, poor metabolic control can lead to impaired development in children and early onset of circulatory complications (vascular involvement).
The classic clinical picture of excessive thirst (polydipsia), frequent urination (polyuria), and weight loss may be absent, and diagnosis may be delayed or even completely missed.