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.
Persons with diabetes are prone to infection, delayed healing, and vascular disease. The ease with which poorly controlled diabetic persons develop an infection is thought to be due in part to decreased chemotaxis of leukocytes, abnormal phagocyte function, and diminished blood supply because of atherosclerotic changes in the blood vessels. An impaired blood supply means a deficit in the protective defensive cells transported in the blood. Excessive glucose allows organisms to grow out of control.

In autoimmune diseases, such as type 1 diabetes, the immune system mistakenly manufactures antibodies and inflammatory cells that are directed against and cause damage to patients' own body tissues. In persons with type 1 diabetes, the beta cells of the pancreas, which are responsible for insulin production, are attacked by the misdirected immune system. It is believed that the tendency to develop abnormal antibodies in type 1 diabetes is, in part, genetically inherited, though the details are not fully understood.
There are many complications of diabetes. Knowing and understanding the signs of these complications is important. If caught early, some of these complications can be treated and prevented from getting worse. The best way to prevent complications of diabetes is to keep your blood sugars in good control. High glucose levels produce changes in the blood vessels themselves, as well as in blood cells (primarily erythrocytes) that impair blood flow to various organs.
All you need to know about insulin sensitivity factor Insulin sensitivity factor is a measurement that describes how blood sugar levels are affected by taking 1 unit of insulin. It can help a person with type 1 diabetes regulate their blood sugar levels. Learn more about what insulin sensitivity factor is, who should test and when, and what the results mean. Read now
People who are obese -- more than 20% over their ideal body weight for their height -- are at particularly high risk of developing type 2 diabetes and its related medical problems. Obese people have insulin resistance. With insulin resistance, the pancreas has to work overly hard to produce more insulin. But even then, there is not enough insulin to keep sugars normal.

The classic symptoms of diabetes such as polyuria, polydypsia and polyphagia occur commonly in type 1 diabetes, which has a rapid development of severe hyperglycaemia and also in type 2 diabetes with very high levels of hyperglycaemia. Severe weight loss is common only in type 1 diabetes or if type 2 diabetes remains undetected for a long period. Unexplained weight loss, fatigue and restlessness and body pain are also common signs of undetected diabetes. Symptoms that are mild or have gradual development could also remain unnoticed.
And remember not to let others scare you into thinking the worst. Getting educated will help you to understand that a diabetes diagnosis, while serious, is not the end of the world. For some people, lifestyle modifications such as weight loss, healthy eating, and exercise can actually get blood sugars below the diabetes threshold. You can control your diabetes and not let it control you.

Nerve damage from diabetes is called diabetic neuropathy and is also caused by disease of small blood vessels. In essence, the blood flow to the nerves is limited, leaving the nerves without blood flow, and they get damaged or die as a result (a term known as ischemia). Symptoms of diabetic nerve damage include numbness, burning, and aching of the feet and lower extremities. When the nerve disease causes a complete loss of sensation in the feet, patients may not be aware of injuries to the feet, and fail to properly protect them. Shoes or other protection should be worn as much as possible. Seemingly minor skin injuries should be attended to promptly to avoid serious infections. Because of poor blood circulation, diabetic foot injuries may not heal. Sometimes, minor foot injuries can lead to serious infection, ulcers, and even gangrene, necessitating surgical amputation of toes, feet, and other infected parts.
The symptoms may relate to fluid loss and polyuria, but the course may also be insidious. Diabetic animals are more prone to infections. The long-term complications recognized in humans are much rarer in animals. The principles of treatment (weight loss, oral antidiabetics, subcutaneous insulin) and management of emergencies (e.g. ketoacidosis) are similar to those in humans.[123]
Type 2 diabetes, which is often diagnosed when a person has an A1C of at least 7 on two separate occasions, can lead to potentially serious issues, like neuropathy, or nerve damage; vision problems; an increased risk of heart disease; and other diabetes complications. A person’s A1C is the two- to three-month average of his or her blood sugar levels.