Type 2 diabetes was once rare in children and adolescents but has recently become more common. However, it usually begins in people older than 30 and becomes progressively more common with age. About 26% of people older than 65 have type 2 diabetes. People of certain racial and ethnic backgrounds are at increased risk of developing type 2 diabetes: blacks, Asian Americans, American Indians, and people of Spanish or Latin American ancestry who live in the United States have a twofold to threefold increased risk as compared with whites. Type 2 diabetes also tends to run in families.

Diabetes mellitus is a chronic disease caused by inherited and/or acquired deficiency in production of insulin by the pancreas, or by the ineffectiveness of the insulin produced. Such a deficiency results in increased concentrations of glucose in the blood, which in turn damage many of the body's systems, in particular the blood vessels and nerves.

Longer-term, the goals of treatment are to prolong life, reduce symptoms, and prevent diabetes-related complications such as blindness, kidney failure, and amputation of limbs. These goals are accomplished through education, insulin use, meal planning and weight control, exercise, foot care, and careful self-testing of blood glucose levels. Self-testing of blood glucose is accomplished through regular use of a blood glucose monitor (pictured, right). This machine can quickly and easily measure the level of blood glucose based by analysing the level from a small drop of blood that is usually obtained from the tip of a finger. You will also require regular tests for glycated haemoglobin (HbA1c). This measures your overall control over several months.
Type 1 diabetes is considered an autoimmune disease. With an autoimmune disease, your immune system – which helps protect your body from getting sick – is engaged in too little or too much activity. In Type 1 diabetes, beta cells, which are a kind of cell in the pancreas that produces insulin, are destroyed. Our bodies use insulin to take the sugar from carbohydrates we eat and create fuel. With Type 1 diabetes, your body does not produce insulin, and that's why you need to use insulin as part of your treatment.

People with type 2 diabetes have insulin resistance, which means the body cannot use insulin properly to help glucose get into the cells. In people with type 2 diabetes, insulin doesn’t work well in muscle, fat, and other tissues, so your pancreas (the organ that makes insulin) starts to put out a lot more of it to try and compensate. "This results in high insulin levels in the body,” says Fernando Ovalle, MD, director of the multidisciplinary diabetes clinic at the University of Alabama in Birmingham. This insulin level sends signals to the brain that your body is hungry.
; DM multiaetiology metabolic disease due to reduced/absent production of pancreatic insulin, and/or insulin resistance by peripheral tissue insulin receptors; characterized by reduced carbohydrate metabolism and increased fat and protein metabolism, leading to hyperglycaemia, increasing glycosuria, water and electrolyte imbalance, ketoacidosis, coma and death if left untreated; chronic long-term complications of DM include nephropathy, retinopathy, neuropathy and generalized degenerative changes in large and small arteries; treatment (with insulin/oral hypoglycaemic agents/diet) aims to stabilize blood glucose levels to the normal range (difficult to achieve fully; patients may tend to hyperglycaemia or hypoglycaemia due to mismanagement of glycaemic control); Tables D4-D7
Being too heavy gets the bulk of the blame for triggering type 2 diabetes. According to the National Institutes of Health, about 85 percent of people with type 2 diabetes are overweight or obese. But consider that the remaining 15 percent are not. Consider, too, that roughly two-thirds of overweight people and a third of those who are obese will never develop diabetes. In other words, normal-weight and thin people also develop type 2, while heavy people won't necessarily. Clearly, there is more to the connection between lifestyle and type 2 diabetes than just body size.

Blood sugar should be regularly monitored so that any problems can be detected and treated early. Treatment involves lifestyle changes such as eating a healthy and balanced diet and regular physical exercise. If lifestyle changes alone are not enough to regulate the blood glucose level, anti-diabetic medication in the form of tablets or injections may be prescribed. In some cases, people who have had type 2 diabetes for many years are eventually prescribed insulin injections.

Some people who have type 2 diabetes can achieve their target blood sugar levels with diet and exercise alone, but many also need diabetes medications or insulin therapy. The decision about which medications are best depends on many factors, including your blood sugar level and any other health problems you have. Your doctor might even combine drugs from different classes to help you control your blood sugar in several different ways.
Fasting plasma glucose level: If your blood glucose level is 7.0 mmol/L or higher after having not eaten anything for at least 8 hours – called fasting – your doctor may diagnose diabetes. If your blood glucose level is between 6.1 to 6.9 mmol/L, your doctor may diagnose impaired fasting glucose or prediabetes (a condition that may later develop into diabetes).
Type 2 diabetes is due to insufficient insulin production from beta cells in the setting of insulin resistance.[13] Insulin resistance, which is the inability of cells to respond adequately to normal levels of insulin, occurs primarily within the muscles, liver, and fat tissue.[44] In the liver, insulin normally suppresses glucose release. However, in the setting of insulin resistance, the liver inappropriately releases glucose into the blood.[10] The proportion of insulin resistance versus beta cell dysfunction differs among individuals, with some having primarily insulin resistance and only a minor defect in insulin secretion and others with slight insulin resistance and primarily a lack of insulin secretion.[13]
Jump up ^ Pignone M, Alberts MJ, Colwell JA, Cushman M, Inzucchi SE, Mukherjee D, Rosenson RS, Williams CD, Wilson PW, Kirkman MS (June 2010). "Aspirin for primary prevention of cardiovascular events in people with diabetes: a position statement of the American Diabetes Association, a scientific statement of the American Heart Association, and an expert consensus document of the American College of Cardiology Foundation". Diabetes Care. 33 (6): 1395–402. doi:10.2337/dc10-0555. PMC 2875463. PMID 20508233.
Good metabolic control can delay the onset and progression of diabetic retinopathy. Loss of vision and blindness in persons with diabetes can be prevented by early detection and treatment of vision-threatening retinopathy: regular eye examinations and timely intervention with laser treatment, or through surgery in cases of advanced retinopathy. There is evidence that, even in developed countries, a large proportion of those in need is not receiving such care due to lack of public and professional awareness, as well as an absence of treatment facilities. In developing countries, in many of which diabetes is now common, such care is inaccessible to the majority of the population.
Per the WHO, people with fasting glucose levels from 6.1 to 6.9 mmol/l (110 to 125 mg/dl) are considered to have impaired fasting glucose.[67] people with plasma glucose at or above 7.8 mmol/l (140 mg/dl), but not over 11.1 mmol/l (200 mg/dl), two hours after a 75 gram oral glucose load are considered to have impaired glucose tolerance. Of these two prediabetic states, the latter in particular is a major risk factor for progression to full-blown diabetes mellitus, as well as cardiovascular disease.[68] The American Diabetes Association (ADA) since 2003 uses a slightly different range for impaired fasting glucose of 5.6 to 6.9 mmol/l (100 to 125 mg/dl).[69]
There are a number of medications and other health problems that can predispose to diabetes.[39] Some of the medications include: glucocorticoids, thiazides, beta blockers, atypical antipsychotics,[40] and statins.[41] Those who have previously had gestational diabetes are at a higher risk of developing type 2 diabetes.[23] Other health problems that are associated include: acromegaly, Cushing's syndrome, hyperthyroidism, pheochromocytoma, and certain cancers such as glucagonomas.[39] Testosterone deficiency is also associated with type 2 diabetes.[42][43]

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.

Insulin is the hormone responsible for reducing blood sugar. In order for insulin to work, our tissues have to be sensitive to its action; otherwise, tissues become resistant and insulin struggles to clear out sugar from the blood. As insulin resistance sets in, the first organ to stop responding to insulin is the liver, followed by the muscles and eventually fat. How does insulin resistance begin? The root of the problem is our diet.
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.
No major organization recommends universal screening for diabetes as there is no evidence that such a program improve outcomes.[54][55] Screening is recommended by the United States Preventive Services Task Force (USPSTF) in adults without symptoms whose blood pressure is greater than 135/80 mmHg.[56] For those whose blood pressure is less, the evidence is insufficient to recommend for or against screening.[56] There is no evidence that it changes the risk of death in this group of people.[55] They also recommend screening among those who are overweight and between the ages of 40 and 70.[57]
A population-based, nationwide cohort study in Finland examined the short -and long-term time trends in mortality among patients with early-onset and late-onset type 1 diabetes. The results suggest that in those with early-onset type 1 diabetes (age 0-14 y), survival has improved over time. Survival of those with late-onset type 1 diabetes (15-29 y) has deteriorated since the 1980s, and the ratio of deaths caused by acute complications has increased in this group. Overall, alcohol was noted as an important cause of death in patients with type 1 diabetes; women had higher standardized mortality ratios than did men in both groups. [38]
Fasting plasma glucose level: If your blood glucose level is 7.0 mmol/L or higher after having not eaten anything for at least 8 hours – called fasting – your doctor may diagnose diabetes. If your blood glucose level is between 6.1 to 6.9 mmol/L, your doctor may diagnose impaired fasting glucose or prediabetes (a condition that may later develop into diabetes).
Beta cells are vulnerable to more than just bad genes, which may explain the associations between type 2 diabetes and environmental factors that aren't related to how much fat a body has or where it is stored. Beta cells carry vitamin D receptors on their surface, and people with vitamin D deficiency are at increased risk for type 2. Plus, several studies have shown that people with higher levels of toxic substances in their blood—such as from the PCBs found in fish fat—are at increased risk of type 2 diabetes, though a cause-and-effect relationship hasn't been proved. (Toxic substances and vitamin D have also been implicated in type 1 diabetes, but the disease mechanism may be unrelated to what's going on in type 2.)
Insulin inhibits glucogenesis and glycogenolysis, while stimulating glucose uptake. In nondiabetic individuals, insulin production by the pancreatic islet cells is suppressed when blood glucose levels fall below 83 mg/dL (4.6 mmol/L). If insulin is injected into a treated child with diabetes who has not eaten adequate amounts of carbohydrates, blood glucose levels progressively fall.

Studies in type 1 patients have shown that in intensively treated patients, diabetic eye disease decreased by 76%, kidney disease decreased by 54%, and nerve disease decreased by 60%. More recently the EDIC trial has shown that type 1 diabetes is also associated with increased heart disease, similar to type 2 diabetes. However, the price for aggressive blood sugar control is a two to three fold increase in the incidence of abnormally low blood sugar levels (caused by the diabetes medications). For this reason, tight control of diabetes to achieve glucose levels between 70 to120 mg/dl is not recommended for children under 13 years of age, patients with severe recurrent hypoglycemia, patients unaware of their hypoglycemia, and patients with far advanced diabetes complications. To achieve optimal glucose control without an undue risk of abnormally lowering blood sugar levels, patients with type 1 diabetes must monitor their blood glucose at least four times a day and administer insulin at least three times per day. In patients with type 2 diabetes, aggressive blood sugar control has similar beneficial effects on the eyes, kidneys, nerves and blood vessels.

Jump up ^ O'Gara PT, Kushner FG, Ascheim DD, Casey DE, Chung MK, de Lemos JA, Ettinger SM, Fang JC, Fesmire FM, Franklin BA, Granger CB, Krumholz HM, Linderbaum JA, Morrow DA, Newby LK, Ornato JP, Ou N, Radford MJ, Tamis-Holland JE, Tommaso CL, Tracy CM, Woo YJ, Zhao DX, Anderson JL, Jacobs AK, Halperin JL, Albert NM, Brindis RG, Creager MA, DeMets D, Guyton RA, Hochman JS, Kovacs RJ, Kushner FG, Ohman EM, Stevenson WG, Yancy CW (January 2013). "2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines". Circulation. 127 (4): e362–425. doi:10.1161/CIR.0b013e3182742cf6. PMID 23247304.
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."

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.

In addition to the problems with an increase in insulin resistance, the release of insulin by the pancreas may also be defective and suboptimal. In fact, there is a known steady decline in beta cell production of insulin in type 2 diabetes that contributes to worsening glucose control. (This is a major factor for many patients with type 2 diabetes who ultimately require insulin therapy.) Finally, the liver in these patients continues to produce glucose through a process called gluconeogenesis despite elevated glucose levels. The control of gluconeogenesis becomes compromised.

The treatment of low blood sugar consists of administering a quickly absorbed glucose source. These include glucose containing drinks, such as orange juice, soft drinks (not sugar-free), or glucose tablets in doses of 15-20 grams at a time (for example, the equivalent of half a glass of juice). Even cake frosting applied inside the cheeks can work in a pinch if patient cooperation is difficult. If the individual becomes unconscious, glucagon can be given by intramuscular injection.

According to the Mayo Clinic, doctors may use other tests to diagnose diabetes. For example, they may conduct a fasting blood glucose test, which is a blood glucose test done after a night of fasting. While a fasting blood sugar level of less than 100 milligrams per deciliter (mg/dL) is normal, one that is between 100 to 125 mg/dL signals prediabetes, and a reading that reaches 126 mg/dL on two separate occasions means you have diabetes.