The food that people eat provides the body with glucose, which is used by the cells as a source of energy. If insulin isn't available or doesn't work correctly to move glucose from the blood into cells, glucose will stay in the blood. High blood glucose levels are toxic, and cells that don't get glucose are lacking the fuel they need to function properly.
Visual impairment and blindness are common sequelae of uncontrolled diabetes. The three most frequently occurring problems involving the eye are diabetic retinopathy, cataracts, and glaucoma. photocoagulation of destructive lesions of the retina with laser beams can be used to delay further progress of pathologic changes and thereby preserve sight in the affected eye.
Type I diabetes, sometimes called juvenile diabetes, begins most commonly in childhood or adolescence. In this form of diabetes, the body produces little or no insulin. It is characterized by a sudden onset and occurs more frequently in populations descended from Northern European countries (Finland, Scotland, Scandinavia) than in those from Southern European countries, the Middle East, or Asia. In the United States, approximately three people in 1,000 develop Type I diabetes. This form also is called insulin-dependent diabetes because people who develop this type need to have daily injections of insulin.
Diabetes is among the leading causes of kidney failure, but its frequency varies between populations and is also related to the severity and duration of the disease. Several measures to slow down the progress of renal damage have been identified. They include control of high blood glucose, control of high blood pressure, intervention with medication in the early stage of kidney damage, and restriction of dietary protein. Screening and early detection of diabetic kidney disease are an important means of prevention.

For example, the environmental trigger may be a virus or chemical toxin that upsets the normal function of the immune system. This may lead to the body’s immune system attacking itself. The normal beta cells in the pancreas may be attacked and destroyed. When approximately 90% of the beta cells are destroyed, symptoms of diabetes mellitus begin to appear. The exact cause and sequence is not fully understood but investigation and research into the disease continues.
But preventing the disease from progressing if you already have it requires first being able to spot the signs and symptoms of diabetes when they appear. While some type 2 diabetes symptoms may not ever show up, you can watch out for the following common signs of the disease and alert your doctor, especially if you have any of the common risk factors for diabetes. Also keep in mind that while most signs of type 2 diabetes are the same in men and women, there are some distinctions.