"Secondary" diabetes refers to elevated blood sugar levels from another medical condition. Secondary diabetes may develop when the pancreatic tissue responsible for the production of insulin is destroyed by disease, such as chronic pancreatitis (inflammation of the pancreas by toxins like excessive alcohol), trauma, or surgical removal of the pancreas.
In type 1 diabetes, other symptoms to watch for include unexplained weight loss, lethargy, drowsiness, and hunger. Symptoms sometimes occur after a viral illness. In some cases, a person may reach the point of diabetic ketoacidosis (DKA) before a type 1 diagnosis is made. DKA occurs when blood glucose is dangerously high and the body can't get nutrients into the cells because of the absence of insulin. The body then breaks down muscle and fat for energy, causing an accumulation of ketones in the blood and urine. Symptoms of DKA include a fruity odor on the breath; heavy, taxed breathing; and vomiting. If left untreated, DKA can result in stupor, unconsciousness, and even death.
Impaired glucose tolerance (IGT) and impaired fasting glycaemia (IFG) refer to levels of blood glucose concentration above the normal range, but below those which are diagnostic for diabetes. Subjects with IGT and/or IFG are at substantially higher risk of developing diabetes and cardiovascular disease than those with normal glucose tolerance. The benefits of clinical intervention in subjects with moderate glucose intolerance is a topic of much current interest.
Every cell in the human body needs energy in order to function. The body's primary energy source is glucose, a simple sugar resulting from the digestion of foods containing carbohydrates (sugars and starches). Glucose from the digested food circulates in the blood as a ready energy source for any cells that need it. Insulin is a hormone or chemical produced by cells in the pancreas, an organ located behind the stomach. Insulin bonds to a receptor site on the outside of cell and acts like a key to open a doorway into the cell through which glucose can enter. Some of the glucose can be converted to concentrated energy sources like glycogen or fatty acids and saved for later use. When there is not enough insulin produced or when the doorway no longer recognizes the insulin key, glucose stays in the blood rather entering the cells.
Fatigue and muscle weakness occur because the glucose needed for energy simply is not metabolized properly. Weight loss in type 1 diabetes patients occurs partly because of the loss of body fluid and partly because in the absence of sufficient insulin the body begins to metabolize its own proteins and stored fat. The oxidation of fats is incomplete, however, and the fatty acids are converted into ketone bodies. When the kidney is no longer able to handle the excess ketones the patient develops ketosis. The overwhelming presence of the strong organic acids in the blood lowers the pH and leads to severe and potentially fatal ketoacidosis.
After a diagnosis of diabetes mellitus has been made, and treatment with insulin therapy has begun, a so-called ‘honeymoon stage’ may develop. This stage is characterised by a reduction in insulin requirements which may last from weeks to months. Some patients may require no insulin at all. This stage is always transient (short-lasting) and is due to production of insulin by the remaining surviving pancreatic beta cells. Eventually, these cells will be destroyed by the on-going auto-immune process, and the patient will be dependent on exogenous (artificial) insulin.
Autonomic changes involving cardiovascular control (eg, heart rate, postural responses) have been described in as many as 40% of children with diabetes. Cardiovascular control changes become more likely with increasing duration and worsening control.  In a study by 253 patients with type 1 diabetes (mean age at baseline 14.4 y), Cho et al reported that the prevalence of cardiac autonomic dysfunction increases in association with higher body mass index and central adiposity. 
The good news is that behavior still seems to help shape whether someone with the genetic disposition actually develops type 2—and that changes in diet and exercise can sometimes be enough to ward off the disease. "People sometimes have the misconception that if we say something is genetic, then they can't do anything about preventing diabetes and its complications," says Hanis. But he notes that in a landmark study, lifestyle interventions prevented or delayed type 2 in nearly 60 percent of people at high risk. "If we focus on changing the environment, we can prevent diabetes," he says. "As we understand the genetics, we can prevent more of it."
There is no single gene that “causes” type 1 diabetes. Instead, there are a large number of inherited factors that may increase an individual’s likelihood of developing diabetes. This is known as multifactorial inheritance. The genes implicated in the development of type 1 diabetes mellitus control the human leukocyte antigen (HLA) system. This system is involved in the complex process of identifying cells which are a normal part of the body, and distinguishing them from foreign cells, such as those of bacteria or viruses. In an autoimmune disease such as diabetes mellitus, this system makes a mistake in identifying the normal ‘self’ cells as ‘foreign’, and attacks the body.
Regarding age, data shows that for each decade after 40 years of age regardless of weight there is an increase in incidence of diabetes. The prevalence of diabetes in persons 65 years of age and older is around 25%. Type 2 diabetes is also more common in certain ethnic groups. Compared with a 7% prevalence in non-Hispanic Caucasians, the prevalence in Asian Americans is estimated to be 8.0%, in Hispanics 13%, in blacks around 12.3%, and in certain Native American communities 20% to 50%. Finally, diabetes occurs much more frequently in women with a prior history of diabetes that develops during pregnancy (gestational diabetes).
People with type 1 diabetes sometimes receive transplantation of an entire pancreas or of only the insulin-producing cells from a donor pancreas. This procedure may allow people with type 1 diabetes mellitus to maintain normal glucose levels. However, because immunosuppressant drugs must be given to prevent the body from rejecting the transplanted cells, pancreas transplantation is usually done only in people who have serious complications due to diabetes or who are receiving another transplanted organ (such as a kidney) and will require immunosuppressant drugs anyway.
High blood sugar (hyperglycemia). Your blood sugar level can rise for many reasons, including eating too much, being sick or not taking enough glucose-lowering medication. Check your blood sugar level often, and watch for signs and symptoms of high blood sugar — frequent urination, increased thirst, dry mouth, blurred vision, fatigue and nausea. If you have hyperglycemia, you'll need to adjust your meal plan, medications or both.
Individuals with diabetes have two times the likelihood of getting a urinary tract infection compared to individuals without the disease. If you find yourself getting up every couple of hours in the middle of the night, and you seem to be expelling a lot more urine than you used to, talk to your doctor and find out whether or not you have diabetes.
Most cases (95%) of type 1 diabetes mellitus are the result of environmental factors interacting with a genetically susceptible person. This interaction leads to the development of autoimmune disease directed at the insulin-producing cells of the pancreatic islets of Langerhans. These cells are progressively destroyed, with insulin deficiency usually developing after the destruction of 90% of islet cells.
Treatment of pituitary diabetes insipidus consists of administration of vasopressin. A synthetic analogue of vasopressin (DDAVP) can be administered as a nasal spray, providing antidiuretic activity for 8 to 20 hours, and is currently the drug of choice. Patient care includes instruction in self-administration of the drug, its expected action, symptoms that indicate a need to adjust the dosage, and the importance of follow-up visits. Patients with this condition should wear some form of medical identification at all times.
Dr. Balentine received his undergraduate degree from McDaniel College in Westminster, Maryland. He attended medical school at the Philadelphia College of Osteopathic Medicine graduating in1983. He completed his internship at St. Joseph's Hospital in Philadelphia and his Emergency Medicine residency at Lincoln Medical and Mental Health Center in the Bronx, where he served as chief resident.
Type 2 diabetes is believed to have a strong genetic link, meaning that it tends to run in families. Several genes are being studied that may be related to the cause of type 2 diabetes. If you have any of the following type 2 diabetes risk factors, it’s important to ask your doctor about a diabetes test. With a proper diabetes diet and healthy lifestyle habits, along with diabetes medication, if necessary, you can manage type 2 diabetes just like you manage other areas of your life. Be sure to continue seeking the latest information on type 2 diabetes as you become your own health advocate.
Recognizing the symptoms of Type 1 diabetes is critical. Although Type 1 develops gradually, as the body’s insulin production decreases, blood glucose levels can become dangerously high once insulin production is outpaced. Symptoms may develop rapidly and can be mistaken for other illnesses such as the flu and a delayed diagnosis can have serious consequences.
Low blood sugar (hypoglycemia). If your blood sugar level drops below your target range, it's known as low blood sugar (hypoglycemia). Your blood sugar level can drop for many reasons, including skipping a meal, inadvertently taking more medication than usual or getting more physical activity than normal. Low blood sugar is most likely if you take glucose-lowering medications that promote the secretion of insulin or if you're taking insulin.
When you have type 2 diabetes, your cells don't get enough glucose, which may cause you to lose weight. Also, if you are urinating more frequently because of uncontrolled diabetes, you may lose more calories and water, resulting in weight loss, says Daniel Einhorn, MD, medical director of the Scripps Whittier Diabetes Institute and clinical professor of medicine at the University of California in San Diego.