Type 2 diabetes is usually associated with being overweight (BMI greater than 25), and is harder to control when food choices are not adjusted, and you get no physical activity. And while it’s true that too much body fat and physical inactivity (being sedentary) does increase the likelihood of developing type 2, even people who are fit and trim can develop this type of diabetes.2,3
Finally, modern society should probably shoulder at least some of the blame for the type 2 diabetes epidemic. Access to cheap, calorie-laden foods may even influence type 2 risk beyond simply their effects on body weight; the stuff that is in processed foods, like high-fructose corn syrup, could alter the body's chemistry or gut microbes in a way that affects health. Add to that the fact that most Americans are sedentary, spending their time sitting in cubicles, driving in cars, playing video games, or watching television. The lack of exercise, plus the abundance of unhealthy foods, cultivates a fertile breeding ground for diabetes.
Hyperglycemic hyperosmolar nonketotic syndrome (HHNS). Signs and symptoms of this life-threatening condition include a blood sugar reading higher than 600 mg/dL (33.3 mmol/L), dry mouth, extreme thirst, fever greater than 101 F (38 C), drowsiness, confusion, vision loss, hallucinations and dark urine. Your blood sugar monitor may not be able to give you an exact reading at such high levels and may instead just read "high."
DM affects at least 16 million U.S. residents, ranks seventh as a cause of death in the United States, and costs the national economy over $100 billion yearly. The striking increase in the prevalence of DM in the U.S. during recent years has been linked to a rise in the prevalence of obesity. About 95% of those with DM have Type 2, in which the pancreatic beta cells retain some insulin-producing potential, and the rest have Type 1, in which exogenous insulin is required for long-term survival. In Type 1 DM, which typically causes symptoms before age 25, an autoimmune process is responsible for beta cell destruction. Type 2 DM is characterized by insulin resistance in peripheral tissues as well as a defect in insulin secretion by beta cells. Insulin regulates carbohydrate metabolism by mediating the rapid transport of glucose and amino acids from the circulation into muscle and other tissue cells, by promoting the storage of glucose in liver cells as glycogen, and by inhibiting gluconeogenesis. The normal stimulus for the release of insulin from the pancreas is a rise in the concentration of glucose in circulating blood, which typically occurs within a few minutes after a meal. When such a rise elicits an appropriate insulin response, so that the blood level of glucose falls again as it is taken into cells, glucose tolerance is said to be normal. The central fact in DM is an impairment of glucose tolerance of such a degree as to threaten or impair health. Long recognized as an independent risk factor for cardiovascular disease, DM is often associated with other risk factors, including disorders of lipid metabolism (elevation of very-low-density lipoprotein cholesterol and triglycerides and depression of high-density lipoprotein cholesterol), obesity, hypertension, and impairment of renal function. Sustained elevation of serum glucose and triglycerides aggravates the biochemical defect inherent in DM by impairing insulin secretion, insulin-mediated glucose uptake by cells, and hepatic regulation of glucose output. Long-term consequences of the diabetic state include macrovascular complications (premature or accelerated atherosclerosis with resulting coronary, cerebral, and peripheral vascular insufficiency) and microvascular complications (retinopathy, nephropathy, and neuropathy). It is estimated that half those with DM already have some complications when the diagnosis is made. The American Diabetes Association (ADA) recommends screening for DM for people with risk factors such as obesity, age 45 years or older, family history of DM, or history of gestational diabetes. If screening yields normal results, it should be repeated every 3 years. The diagnosis of DM depends on measurement of plasma glucose concentration. The diagnosis is confirmed when any two measurements of plasma glucose performed on different days yield levels at or above established thresholds: in the fasting state, 126 mg/dL (7 mmol/L); 2 hours postprandially (after a 75-g oral glucose load) or at random, 200 mg/dL (11.1 mmol/L). A fasting plasma glucose of 100-125 mg/dL (5.5-6.9 mmol/L) or a 2-hour postprandial glucose of 140-199 mg/dL (7.8-11 mmol/L) is defined as impaired glucose tolerance. People with impaired glucose tolerance are at higher risk of developing DM within 10 years. For such people, lifestyle modification such as weight reduction and exercise may prevent or postpone the onset of frank DM. Current recommendations for the management of DM emphasize education and individualization of therapy. Controlled studies have shown that rigorous maintenance of plasma glucose levels as near to normal as possible at all times substantially reduces the incidence and severity of long-term complications, particularly microvascular complications. Such control involves limitation of dietary carbohydrate and saturated fat; monitoring of blood glucose, including self-testing by the patient and periodic determination of glycosylated hemoglobin; and administration of insulin (particularly in Type 1 DM), drugs that stimulate endogenous insulin production (in Type 2 DM), or both. The ADA recommends inclusion of healthful carbohydrate-containing foods such as whole grains, fruits, vegetables, and low-fat milk in a diabetic diet. Restriction of dietary fat to less than 10% of total calories is recommended for people with diabetes, as for the general population. Further restriction may be appropriate for those with heart disease or elevated cholesterol or triglyceride levels. The ADA advises that high-protein, low-carbohydrate diets have no particular merit in long-term weight control or in maintenance of a normal plasma glucose level in DM. Pharmaceutical agents developed during the 1990s improve control of DM by enhancing responsiveness of cells to insulin, counteracting insulin resistance, and reducing postprandial carbohydrate absorption. Tailor-made insulin analogues produced by recombinant DNA technology (for example, lispro, aspart, and glargine insulins) have broadened the range of pharmacologic properties and treatment options available. Their use improves both short-term and long-term control of plasma glucose and is associated with fewer episodes of hypoglycemia. SEE ALSO insulin resistance
In the exchange system, foods are divided into six food groups (starch, meat, vegetable, fruit, milk, and fat) and the patient is taught to select items from each food group as ordered. Items in each group may be exchanged for each other in specified portions. The patient should avoid concentrated sweets and should increase fiber in the diet. Special dietetic foods are not necessary. Patient teaching should emphasize that a diabetic diet is a healthy diet that all members of the family can follow.
What is type 2 diabetes and prediabetes? Behind type 2 diabetes is a disease where the body’s cells have trouble responding to insulin – this is called insulin resistance. Insulin is a hormone needed to store the energy found in food into the body’s cells. In prediabetes, insulin resistance starts growing and the beta cells in the pancreas that release insulin will try to make even more insulin to make up for the body’s insensitivity. This can go on for a long time without any symptoms. Over time, though, the beta cells in the pancreas will fatigue and will no longer be able to produce enough insulin – this is called “beta burnout.” Once there is not enough insulin, blood sugars will start to rise above normal. Prediabetes causes people to have higher-than-normal blood sugars (and an increased risk for heart disease and stroke). Left unnoticed or untreated, blood sugars continue to worsen and many people progress to type 2 diabetes. After a while, so many of the beta cells have been damaged that diabetes becomes an irreversible condition. 
Your body is like a car—it needs fuel to function. Its primary source of fuel is glucose (sugar), which is gained from foods that contain carbohydrates that get broken down. Insulin, a hormone produced by the pancreas, takes sugar from your blood to your cells to use for energy. However, when you have diabetes, either your pancreas isn't making enough insulin or the insulin that your body is making isn't being used the way it's supposed to be, typically because the cells become resistant to it.

People with these risk factors should be screened for diabetes at least once every three years. Diabetes risk can be estimated using online risk calculators. Doctors may measure fasting blood glucose levels and hemoglobin A1C level, or do an oral glucose tolerance test. If the test results are on the border between normal and abnormal, doctors do the screening tests more often, at least once a year.
^ Jump up to: a b Funnell, Martha M.; Anderson, Robert M. (2008). "Influencing self-management: from compliance to collaboration". In Feinglos, Mark N.; Bethel, M. Angelyn. Type 2 diabetes mellitus: an evidence-based approach to practical management. Contemporary endocrinology. Totowa, NJ: Humana Press. p. 462. ISBN 978-1-58829-794-5. OCLC 261324723.
Monogenic diabetes is caused by mutations, or changes, in a single gene. These changes are usually passed through families, but sometimes the gene mutation happens on its own. Most of these gene mutations cause diabetes by making the pancreas less able to make insulin. The most common types of monogenic diabetes are neonatal diabetes and maturity-onset diabetes of the young (MODY). Neonatal diabetes occurs in the first 6 months of life. Doctors usually diagnose MODY during adolescence or early adulthood, but sometimes the disease is not diagnosed until later in life.
Since diabetes can be life-threatening if not properly managed, patients should not attempt to treat this condition without medicial supervision. A variety of alternative therapies can be helpful in managing the symptoms of diabetes and supporting patients with the disease. Acupuncture can help relieve the pain associated with diabetic neuropathy by stimulation of cetain points. A qualified practitioner should be consulted. Herbal remedies also may be helpful in managing diabetes. Although there is no herbal substitute for insulin, some herbs may help adjust blood sugar levels or manage other diabetic symptoms. Some options include:
Since diabetes can be life-threatening if not properly managed, patients should not attempt to treat this condition without medicial supervision. A variety of alternative therapies can be helpful in managing the symptoms of diabetes and supporting patients with the disease. Acupuncture can help relieve the pain associated with diabetic neuropathy by stimulation of cetain points. A qualified practitioner should be consulted. Herbal remedies also may be helpful in managing diabetes. Although there is no herbal substitute for insulin, some herbs may help adjust blood sugar levels or manage other diabetic symptoms. Some options include:
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.
Type 2 Diabetes: Accounting for 90 to 95 percent of those with diabetes, type 2 is the most common form. Usually, it's diagnosed in adults over age 40 and 80 percent of those with type 2 diabetes are overweight. Because of the increase in obesity, type 2 diabetes is being diagnosed at younger ages, including in children. Initially in type 2 diabetes, insulin is produced, but the insulin doesn't function properly, leading to a condition called insulin resistance. Eventually, most people with type 2 diabetes suffer from decreased insulin production.
Insulin — the hormone that allows your body to regulate sugar in the blood — is made in your pancreas. Essentially, insulin resistance is a state in which the body’s cells do not use insulin efficiently. As a result, it takes more insulin than normal to transport blood sugar (glucose) into cells, to be used immediately for fuel or stored for later use. A drop in efficiency in getting glucose to cells creates a problem for cell function; glucose is normally the body’s quickest and most readily available source of energy.
It is clearly established that diabetes mellitus is not a single disease but a genetically heterogeneous group of disorders that share glucose intolerance in common (4–7). The concept of genetic heterogeneity (i.e. that different genetic and/or environmental etiologic factors can result in similar phenotypes) has significantly altered the genetic analysis of this common disorder. Diabetes and glucose intolerance are not diagnostic terms, but, like anemia, simply describe symptoms and/or laboratory abnormalities that can have a number of distinct etiologies.
Jump up ^ Zheng, Sean L.; Roddick, Alistair J.; Aghar-Jaffar, Rochan; Shun-Shin, Matthew J.; Francis, Darrel; Oliver, Nick; Meeran, Karim (17 April 2018). "Association Between Use of Sodium-Glucose Cotransporter 2 Inhibitors, Glucagon-like Peptide 1 Agonists, and Dipeptidyl Peptidase 4 Inhibitors With All-Cause Mortality in Patients With Type 2 Diabetes". JAMA. 319 (15): 1580. doi:10.1001/jama.2018.3024.

Diabetic peripheral neuropathy is a condition where nerve endings, particularly in the legs and feet, become less sensitive. Diabetic foot ulcers are a particular problem since the patient does not feel the pain of a blister, callous, or other minor injury. Poor blood circulation in the legs and feet contribute to delayed wound healing. The inability to sense pain along with the complications of delayed wound healing can result in minor injuries, blisters, or callouses becoming infected and difficult to treat. In cases of severe infection, the infected tissue begins to break down and rot away. The most serious consequence of this condition is the need for amputation of toes, feet, or legs due to severe infection.
Insulin is a hormone that is produced by specialized cells (beta cells) of the pancreas. (The pancreas is a deep-seated organ in the abdomen located behind the stomach.) In addition to helping glucose enter the cells, insulin is also important in tightly regulating the level of glucose in the blood. After a meal, the blood glucose level rises. In response to the increased glucose level, the pancreas normally releases more insulin into the bloodstream to help glucose enter the cells and lower blood glucose levels after a meal. When the blood glucose levels are lowered, the insulin release from the pancreas is turned down. It is important to note that even in the fasting state there is a low steady release of insulin than fluctuates a bit and helps to maintain a steady blood sugar level during fasting. In normal individuals, such a regulatory system helps to keep blood glucose levels in a tightly controlled range. As outlined above, in patients with diabetes, the insulin is either absent, relatively insufficient for the body's needs, or not used properly by the body. All of these factors cause elevated levels of blood glucose (hyperglycemia).

People with Type 1 diabetes are usually totally dependent on insulin injections for survival. Such people require daily administration of insulin. The majority of people suffering from diabetes have the Type 2 form. Although they do not depend on insulin for survival, about one third of sufferers needs insulin for reducing their blood glucose levels.
The typical symptoms of diabetes mellitus are the three “polys:” polyuria, polydipsia, and polyphagia. Because of insulin deficiency, the assimilation and storage of glucose in muscle adipose tissues, and the liver is greatly diminished. This produces an accumulation of glucose in the blood and creates an increase in its osmolarity. In response to this increased osmotic pressure there is depletion of intracellular water and osmotic diuresis. The water loss creates intense thirst and increased urination. The increased appetite (polyphagia) is not as clearly understood. It may be the result of the body's effort to increase its supply of energy foods even though eating more carbohydrates in the absence of sufficient insulin does not meet the energy needs of the cells.
If you are symptomatic (e.g., increased thirst or urination, unexplained weight loss), your doctor may only use a single test to diagnose diabetes/prediabetes. If you don't have any symptoms, one high blood glucose test doesn't necessarily mean you have diabetes/prediabetes. Your doctor will repeat one of the blood tests again on another day (generally 1 week later) to confirm the diagnosis.
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.

Intensive blood sugar lowering (HbA1c<6%) as opposed to standard blood sugar lowering (HbA1c of 7–7.9%) does not appear to change mortality.[74][75] The goal of treatment is typically an HbA1c of 7 to 8% or a fasting glucose of less than 7.2 mmol/L (130 mg/dl); however these goals may be changed after professional clinical consultation, taking into account particular risks of hypoglycemia and life expectancy.[59][76][77] Despite guidelines recommending that intensive blood sugar control be based on balancing immediate harms with long-term benefits, many people – for example people with a life expectancy of less than nine years who will not benefit, are over-treated.[78]
Normally, blood glucose levels are tightly controlled by insulin, a hormone produced by the pancreas. Insulin lowers the blood glucose level. When the blood glucose elevates (for example, after eating food), insulin is released from the pancreas to normalize the glucose level by promoting the uptake of glucose into body cells. In patients with diabetes, the absence of insufficient production of or lack of response to insulin causes hyperglycemia. Diabetes is a chronic medical condition, meaning that although it can be controlled, it lasts a lifetime.

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.  
Insulin is a hormone made by your pancreas that acts like a key to let blood sugar into the cells in your body for use as energy. If you have type 2 diabetes, cells don’t respond normally to insulin; this is called insulin resistance. Your pancreas makes more insulin to try to get cells to respond. Eventually your pancreas can’t keep up, and your blood sugar rises, setting the stage for prediabetes and type 2 diabetes. High blood sugar is damaging to the body and can cause other serious health problems, such as heart disease, vision loss, and kidney disease.
Glucose is a simple sugar found in food. Glucose is an essential nutrient that provides energy for the proper functioning of the body cells. Carbohydrates are broken down in the small intestine and the glucose in digested food is then absorbed by the intestinal cells into the bloodstream, and is carried by the bloodstream to all the cells in the body where it is utilized. However, glucose cannot enter the cells alone and needs insulin to aid in its transport into the cells. Without insulin, the cells become starved of glucose energy despite the presence of abundant glucose in the bloodstream. In certain types of diabetes, the cells' inability to utilize glucose gives rise to the ironic situation of "starvation in the midst of plenty". The abundant, unutilized glucose is wastefully excreted in the urine.
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.