a broadly applied term used to denote a complex group of syndromes that have in common a disturbance in the oxidation and utilization of glucose, which is secondary to a malfunction of the beta cells of the pancreas, whose function is the production and release of insulin. Because insulin is involved in the metabolism of carbohydrates, proteins and fats, diabetes is not limited to a disturbance of glucose homeostasis alone.

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. [18] 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. [19]

Diabetes mellitus occurs throughout the world but is more common (especially type 2) in more developed countries. The greatest increase in rates has however been seen in low- and middle-income countries,[101] where more than 80% of diabetic deaths occur.[105] The fastest prevalence increase is expected to occur in Asia and Africa, where most people with diabetes will probably live in 2030.[106] The increase in rates in developing countries follows the trend of urbanization and lifestyle changes, including increasingly sedentary lifestyles, less physically demanding work and the global nutrition transition, marked by increased intake of foods that are high energy-dense but nutrient-poor (often high in sugar and saturated fats, sometimes referred to as the "Western-style" diet).[101][106] The global prevalence of diabetes might increase by 55% between 2013 and 2035.[101]

To treat diabetic retinopathy, a laser is used to destroy and prevent the recurrence of the development of these small aneurysms and brittle blood vessels. Approximately 50% of patients with diabetes will develop some degree of diabetic retinopathy after 10 years of diabetes, and 80% retinopathy after 15 years of the disease. Poor control of blood sugar and blood pressure further aggravates eye disease in diabetes.
Diet, exercise, and education are the cornerstones of treatment of diabetes and often the first recommendations for people with mild diabetes. Weight loss is important for people who are overweight. People who continue to have elevated blood glucose levels despite lifestyle changes, or have very high blood glucose levels and people with type 1 diabetes (no matter their blood glucose levels) also require drugs.
Janis McWilliams, RN, MSN, CDE, BC-ADM, responds: Yes, in type 1 diabetes in particular, the onset of symptoms like frequent urination and extreme thirst can be very sudden. In type 2 diabetes, the symptoms tend to come about more gradually, and sometimes there are no signs at all. People who have symptoms should contact their health care provider immediately for an accurate diagnosis. Keep in mind that these symptoms could signal other problems, too.
It is a considerable challenge to obtain the goals of the intensively treated patients in the DCCT with the vast majority of people with diabetes given the more limited health care resources typically available in routine practice. If diabetes control can be improved without significant damage to quality of life, the economic, health, and quality of life savings associated with a reduction in complications in later life will be vast. Although some people who have had poorly controlled diabetes over many years do not develop complications, complications commonly arise after 15–20 years of diabetes and individuals in their 40s or even 30s may develop several complications in rapid succession. However, up until the early 1980s, patients had no way of monitoring their own blood glucose levels at home. Urine glucose monitoring only told them when their blood glucose had exceeded the renal threshold of approximately 10 mmol/L (i.e., was far too high), without being able to discriminate between the too high levels of 7–10 mmol/L or the hypoglycemic levels below 4 mmol/L. Clinics relied on random blood glucose testing and there were no measures of average blood glucose over a longer period. Since the 1980s there have been measures of glycosylated hemoglobin (GHb, HbA1, or HbA1c) which indicate average blood glucose over a six to eight week period and measures of glycosylated protein, fructosamine, which indicates average blood glucose over a two-week period. Blood-glucose meters for patients were first introduced in the early 1980s and the accuracy and convenience of the meters and the reagent strips they use has improved dramatically since early models. By the late 1990s blood-glucose monitoring is part of the daily routine for most people using insulin in developed countries. Blood-glucose monitoring is less often prescribed for tablet- and diet-alone-treated patients, financial reasons probably being allowed to outweigh the educational value of accurate feedback in improving control long term. The reduced risk of hypoglycemia and diabetic ketoacidosis in NIDDM patients not using insulin means that acute crises rarely arise in these patients though their risk of long-term complications is at least as great as in IDDM and might be expected to be reduced if feedback from blood-glucose monitoring were provided.
Persons with diabetes who take insulin must be careful about indulging in unplanned exercise. Strenuous physical activity can rapidly lower their blood sugar and precipitate a hypoglycemic reaction. For a person whose blood glucose level is over 250 mg/dl, the advice would be not to exercise at all. At this range, the levels of insulin are too low and the body would have difficulty transporting glucose into exercising muscles. The result of exercise would be a rise in blood glucose levels.
Exercise. A program of regular exercise gives anyone a sense of good health and well-being; for persons with diabetes it gives added benefits by helping to control blood glucose levels, promoting circulation to peripheral tissues, and strengthening the heart beat. In addition, there is evidence that exercise increases the number of insulin receptor sites on the surface of cells and thus facilitates the metabolism of glucose. Many specialists in diabetes consider exercise so important in the management of diabetes that they prescribe rather than suggest exercise.
Diabetes mellitus is a public health problem around the world. In 1980, 108 million adults worldwide had diabetes (4.7% of the global population). By 2014 this had risen to 422 million adults (8.5% of the global population). By 2040, the number is expected to be 642 million adults. In the UK, there is estimated to be between 3 and 4 million people with diabetes. Type 2 diabetes accounts for more than 90% of all patients with 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.

The amount of glucose in the bloodstream is tightly regulated by insulin and other hormones. Insulin is always being released in small amounts by the pancreas. When the amount of glucose in the blood rises to a certain level, the pancreas will release more insulin to push more glucose into the cells. This causes the glucose levels in the blood (blood glucose levels) to drop.
A study by Mayer-Davis et al indicated that between 2002 and 2012, the incidence of type 1 and type 2 diabetes mellitus saw a significant rise among youths in the United States. According to the report, after the figures were adjusted for age, sex, and race or ethnic group, the incidence of type 1 (in patients aged 0-19 years) and type 2 diabetes mellitus (in patients aged 10-19 years) during this period underwent a relative annual increase of 1.8% and 4.8%, respectively. The greatest increases occurred among minority youths. [29]
Patients need to ensure that their blood glucose levels are kept as normal as possible so that delicate tissues in the body (especially blood vessels in the eyes, kidneys and peripheral nerves) are not damaged by high glucose levels over a long period of time. To achieve this, patients need to measure their glucose regularly and learn how to adjust their insulin doses in order to optimise their glucose levels (diabetes control). Good diabetes control helps to minimise the risk of long-term diabetes complications, as well as short-term symptoms (such as thirst).

Of course, you’re exhausted every now and then. But ongoing fatigue is an important symptom to pay attention to; it might mean the food you’re eating for energy isn’t being broken down and used by cells as it’s supposed to. “You’re not getting the fuel your body needs,” says Dobbins. “You’re going to be tired and feel sluggish.” But in many cases of type 2 diabetes, your sugar levels can be elevated for awhile, so these diabetes symptoms could come on slowly.
Diabetes Mellitus Diabetes Mellitus Complications Diabetes Mellitus Control in Hospital Diabetes Mellitus Glucose Management Diabetes Resources Diabetes Sick Day Management Diabetic Ketoacidosis Diabetic Ketoacidosis Management in Adults Diabetic Ketoacidosis Management in Children Diabetic Ketoacidosis Related Cerebral Edema Hyperosmolar Hyperglycemic State Metabolic Syndrome Type 1 Diabetes Mellitus Type 2 Diabetes Mellitus Type 2 Diabetes Mellitus in Children
Your risk for Type 2 diabetes increases as you get older. It also increases if you smoke. Although smoking doesn't cause diabetes per se, the negative effects on your health are enough to make it more likely that Type 2 diabetes will occur if you have the other risk factors. "We try to be aggressive with smoking cessation, in particular in patients with diabetes," says Dr. Asha M. Thomas, an endocrinologist with Sinai Hospital of Baltimore.
A final note about type 1: Some people have a "honeymoon" period, a brief remission of symptoms while the pancreas is still secreting some insulin. The honeymoon phase typically occurs after insulin treatment has been started. A honeymoon can last as little as a week or even up to a year. But the absence of symptoms doesn't mean the diabetes is gone. The pancreas will eventually be unable to secrete insulin, and, if untreated, the symptoms will return.

The classic presenting symptoms of type 1 diabetes mellitus are discussed below. For some children, the first symptoms of diabetes mellitus are those of diabetic ketoacidosis. This is a serious and life-threatening condition, requiring immediate treatment. Ketoacidosis occurs due to a severe disturbance in the body’s metabolism. Without insulin, glucose cannot be taken up into cells. Instead fats are broken down for energy which can have acid by-products.  

Type 2 diabetes is mainly caused by insulin resistance. This means no matter how much or how little insulin is made, the body can't use it as well as it should. As a result, glucose can't be moved from the blood into cells. Over time, the excess sugar in the blood gradually poisons the pancreas causing it to make less insulin and making it even more difficult to keep blood glucose under control.
2. Home glucose monitoring using either a visually read test or a digital readout of the glucose concentration in a drop of blood. Patients can usually learn to use the necessary equipment and perform finger sticks. They keep a daily record of findings and are taught to adjust insulin dosage accordingly. More recent glucose monitoring devices can draw blood from other locations on the body, such as the forearm.
How is it treated? There is no uniform therapy for type 2 diabetes treatment, which depends on the individual person and his or her stage of type 2 diabetes. To learn more about individualization of therapy, please read our patient guide. That said, the ADA and EASD have created treatment recommendation guidelines for type 2 diabetes progression. In all cases, healthy eating, exercise, and weight management are key to effective type 2 diabetes management. As type 2 diabetes progresses, patients may need to add one or more drugs to their treatment regimen.
Unlike people with type 1 diabetes, people with type 2 diabetes produce insulin; however, the insulin their pancreas secretes is either not enough or the body is unable to recognize the insulin and use it properly (insulin resistance). When there isn't enough insulin or the insulin is not used as it should be, glucose (sugar) can't get into the body's cells and builds up in the bloodstream instead. When glucose builds up in the blood instead of going into cells, it causes damage in multiple areas of the body. Also, since cells aren't getting the glucose they need, they can't function properly.
Does having type 2 diabetes affect life expectancy? While continued improvements in therapies and care for type 2 diabetes may be helping patients live longer, the unfortunate reality is that type 2 diabetes has been shown to decrease life expectancy by up to ten years, according to Diabetes UK. There is still much to be done to ensure that all patients have access to appropriate healthcare and treatments to live a happier and healthier life with type 2 diabetes.
A proper diet and exercise are the foundations of diabetic care,[23] with a greater amount of exercise yielding better results.[80] Exercise improves blood sugar control, decreases body fat content and decreases blood lipid levels, and these effects are evident even without weight loss.[81] Aerobic exercise leads to a decrease in HbA1c and improved insulin sensitivity.[82] Resistance training is also useful and the combination of both types of exercise may be most effective.[82]

Diabetes is a metabolic disorder that occurs when your blood sugar (glucose), is too high (hyperglycemia). Glucose is what the body uses for energy, and the pancreas produces a hormone called insulin that helps convert the glucose from the food you eat into energy. When the body either does not produce enough insulin, does not produce any at all, or your body becomes resistant to the insulin, the glucose does not reach your cells to be used for energy. This results in the health condition termed diabetes.

Excessive hunger goes hand-in-hand with fatigue and cell starvation. Because the cells are resistant to the body's insulin, glucose remains in the blood. The cells are then unable to gain access to glucose, which can trigger hunger hormones that tell the brain that you are hungry. Excessive eating can complicate things further by causing blood sugars to increase.
In type 2 diabetes (formerly called non– insulin-dependent diabetes or adult-onset diabetes), the pancreas often continues to produce insulin, sometimes even at higher-than-normal levels, especially early in the disease. However, the body develops resistance to the effects of insulin, so there is not enough insulin to meet the body’s needs. As type 2 diabetes progresses, the insulin-producing ability of the pancreas decreases.
Also striking are the differences in incidence between mainland Italy (8.4 cases per 100,000 population) and the Island of Sardinia (36.9 cases per 100,000 population). These variations strongly support the importance of environmental factors in the development of type 1 diabetes mellitus. Most countries report that incidence rates have at least doubled in the last 20 years. Incidence appears to increase with distance from the equator. [31]

“It’s not like you wake up one day and all of a sudden you’re thirsty, hungry, and [going to the bathroom] all the time,” says Melissa Joy Dobbins, RD, a certified diabetes educator in Illinois and a spokesperson for the American Association of Diabetes Educators. “It picks up gradually.” Indeed, “most people are unaware that they have diabetes in its early or even middle phases,” says Aaron Cypess, MD, assistant professor of medicine at Harvard Medical School and staff physician at Joslin Diabetes Center. Just because you’re not keyed in doesn’t mean you’re immune from problems associated with diabetes, he adds. The longer you go without controlling diabetes, the greater your risk for heart disease, kidney disease, amputation, blindness, and other serious complications. “We recommend that people with risk factors for diabetes, such as a family history or being overweight, get evaluated on a regular basis,” Dr. Cypess says. If you’ve been feeling off, talk to your doctor about getting a simple blood test that can diagnose the disease. And pay attention to these subtle signs and symptoms of diabetes.
Diabetes mellitus (“diabetes”) and hypertension, which commonly coexist, are global public health issues contributing to an enormous burden of cardiovascular disease, chronic kidney disease, and premature mortality and disability. The presence of both conditions has an amplifying effect on risk for microvascular and macrovascular complications.1 The prevalence of diabetes is rising worldwide (Fig. 37.1). Both diabetes and hypertension disproportionately affect people in middle and low-income countries, and an estimated 70% of all cases of diabetes are found in these countries.2,3 In the United States alone, the total costs of care for diabetes and hypertension in the years 2012 and 2011 were 245 and 46 billion dollars, respectively.4,5 Therefore, there is a great potential for meaningful health and economic gains attached to prevention, detection, and intervention for diabetes and hypertension.
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.
While many experts believe that most type 1 genes have been identified, the situation with type 2 diabetes is much different. A recent study found that the known genetic links to type 2 probably account for only about 6 percent of the genetic predisposition for that form of diabetes. This could mean either that some of the genes discovered have a bigger effect than is currently believed or that "we are still missing 94 percent of the genes," says Atul Butte, MD, PhD, an assistant professor of pediatrics at Stanford University.

Management. There is no cure for diabetes; the goal of treatment is to maintain blood glucose and lipid levels within normal limits and to prevent complications. In general, good control is achieved when the following occur: fasting plasma glucose is within a specific range (set by health care providers and the individual), glycosylated hemoglobin tests show that blood sugar levels have stayed within normal limits from one testing period to the next, the patient's weight is normal, blood lipids remain within normal limits, and the patient has a sense of health and well-being.

Risk factors for type 2 diabetes include obesity, high cholesterol, high blood pressure, and physical inactivity. The risk of developing type 2 diabetes also increases as people grow older. People who are over 40 and overweight are more likely to develop type 2 diabetes, although the incidence of this type of diabetes in adolescents is growing. Diabetes is more common among Native Americans, African Americans, Hispanic Americans and Asian Americans/Pacific Islanders. Also, people who develop diabetes while pregnant (a condition called gestational diabetes) are more likely to develop type 2 diabetes later in life.
A1C: Your A1C, also called glycated hemoglobin, reflects your average blood glucose levels for the past 2 to 3 months. If your A1C is 6.5% or greater, your doctor may diagnose diabetes. If your A1C is between 6.0% and 6.4%, your doctor may diagnose prediabetes. Of note, A1C cannot be used to diagnose type 1 diabetes, diabetes in children, adolescents, or pregnant women.
Indigestion (dyspepsia) can be caused by diseases or conditions that involve the gastrointestinal (GI) tract, and also by some diseases and conditions that do not involve the GI tract. Indigestion can be a chronic condition in which the symptoms fluctuate infrequency and intensity. Signs and symptoms that accompany indigestion include pain in the chest, upper abdominal pain, belching, nausea, bloating, abdominal distention, feeling full after eating only a small portion of food, and rarely, vomiting.