Basic on Diabetes Mellitus
Diabetes mellitus is a syndrome characterized by disordered metabolism and abnormally high blood sugar (hyperglycaemia) resulting from low levels of the hormone insulin.
The World Health Organization classifies three main forms of diabetes mellitus: type 1, type 2, and gestational diabetes (occurring during pregnancy) Type 1 diabetes is usually due to autoimmune destruction of the pancreatic beta cells. Type 2 diabetes is characterized by insulin resistance in target tissues. It is related to obesity. Gestational diabetes is similar to type 2 diabetes because the hormones of pregnancy can cause insulin resistance in women genetically predisposed to developing this condition.
The characteristic symptoms are excessive urine production (polyuria) due to high blood glucose levels, excessive thirst and increased fluid intake (polydipsia) attempting to compensate for increased urination, blurred vision, unexplained weight loss and lethargy. These symptoms are asymptomatic at the beginning of the syndrome.
Type 1 diabetes, insulin is not secreted by the pancreas, it is treatable with injected insulin. Type 2 may be managed with a combination of dietary treatment, tablets and injections and insulin supplementation.
Diabetes can cause many complications. Acute complications (hypoglycemia, ketoacidosis, or nonketotic hyperosmolar coma) may occur if the disease is not adequately controlled. Serious long-term complications include cardiovascular disease (doubled risk), chronic renal failure, retinal damage (which can lead to blindness), nerve damage (of several kinds), and microvascular damage, which may cause impotence and poor healing. Poor healing of wounds, particularly of the feet, can lead to gangrene, which may require amputation.
Adequate treatment of diabetes and increased emphasis on blood pressure control and lifestyle factors (such as not smoking and keeping a healthy body weight), may improve the risk profile of most aforementioned complications.
In the developed world, diabetes is the most significant cause of adult blindness in the non-elderly and the leading cause of non-traumatic amputation in adults, and diabetic nephropathy is the main illness requiring renal dialysis in many countries.