Type 2 diabetes, the most common type of diabetes, is a disease that occurs when your blood glucose, also called blood sugar, is too high. Blood glucose is your main source of energy and comes mainly from the food you eat. Insulin, a hormone made by the pancreas, helps glucose get into your cells to be used for energy. In type 2 diabetes, your body doesn’t make enough insulin or doesn’t use insulin well. Too much glucose then stays in your blood, and not enough reaches your cells.
Type 2 diabetes usually begins with insulin resistance, a condition in which muscle, liver, and fat cells do not use insulin well. As a result, your body needs more insulin to help glucose enter cells. At first, the pancreas makes more insulin to keep up with the added demand. Over time, the pancreas can’t make enough insulin, and blood glucose levels rise.
Insulin is a hormone that — in people without diabetes — ferries glucose, or blood sugar, to cells for energy or to be stored for later use. In people with diabetes, cells are resistant to insulin; as a result of this insulin resistance, sugar accumulates in the blood. While eating sugar by itself does not cause insulin resistance, Grieger says, foods with sugar and fat can contribute to weight gain, thereby reducing insulin sensitivity in the body.
As of 2015, an estimated 415 million people had diabetes worldwide,[8] with type 2 DM making up about 90% of the cases.[16][17] This represents 8.3% of the adult population,[17] with equal rates in both women and men.[18] As of 2014, trends suggested the rate would continue to rise.[19] Diabetes at least doubles a person's risk of early death.[2] From 2012 to 2015, approximately 1.5 to 5.0 million deaths each year resulted from diabetes.[8][9] The global economic cost of diabetes in 2014 was estimated to be US$612 billion.[20] In the United States, diabetes cost $245 billion in 2012.[21]
Jump up ^ Picot, J; Jones, J; Colquitt, JL; Gospodarevskaya, E; Loveman, E; Baxter, L; Clegg, AJ (September 2009). "The clinical effectiveness and cost-effectiveness of bariatric (weight loss) surgery for obesity: a systematic review and economic evaluation". Health Technology Assessment. Winchester, England. 13 (41): iii–iv, 1–190, 215–357. doi:10.3310/hta13410. PMID 19726018.
People with type 1 diabetes and certain people with type 2 diabetes may use carbohydrate counting or the carbohydrate exchange system to match their insulin dose to the carbohydrate content of their meal. "Counting" the amount of carbohydrate in a meal is used to calculate the amount of insulin the person takes before eating. However, the carbohydrate-to-insulin ratio (the amount of insulin taken for each gram of carbohydrate in the meal) varies for each person, and people with diabetes need to work closely with a dietician who has experience in working with people with diabetes to master the technique. Some experts have advised use of the glycemic index (a measure of the impact of an ingested carbohydrate-containing food on the blood glucose level) to delineate between rapid and slowly metabolized carbohydrates, although there is little evidence to support this approach.
Jump up ^ Farmer, AJ; Perera, R; Ward, A; Heneghan, C; Oke, J; Barnett, AH; Davidson, MB; Guerci, B; Coates, V; Schwedes, U; O'Malley, S (27 February 2012). "Meta-analysis of individual patient data in randomised trials of self monitoring of blood glucose in people with non-insulin treated type 2 diabetes". The BMJ. 344: e486. doi:10.1136/bmj.e486. PMID 22371867.
Insulin is a hormone produced by the beta cells within the pancreas in response to the intake of food. The role of insulin is to lower blood sugar (glucose) levels by allowing cells in the muscle, liver and fat to take up sugar from the bloodstream that has been absorbed from food, and store it away as energy. In type 1 diabetes (previously called insulin-dependent diabetes mellitus), the insulin-producing cells are destroyed and the body is not able to produce insulin naturally. This means that sugar is not stored away but is constantly released from energy stores giving rise to high sugar levels in the blood. This in turn causes dehydration and thirst (because the high glucose ‘spills over’ into the urine and pulls water out of the body at the same time). To exacerbate the problem, because the body is not making insulin it ‘thinks’ that it is starving so does everything it can to release even more stores of energy into the bloodstream. So, if left untreated, patients become increasingly unwell, lose weight, and develop a condition called diabetic ketoacidosis, which is due to the excessive release of acidic energy stores and causes severe changes to how energy is used and stored in the body.
The blood vessels and blood are the highways that transport sugar from where it is either taken in (the stomach) or manufactured (in the liver) to the cells where it is used (muscles) or where it is stored (fat). Sugar cannot go into the cells by itself. The pancreas releases insulin into the blood, which serves as the helper, or the "key," that lets sugar into the cells for use as energy.
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.

Jump up ^ Boussageon, R; Bejan-Angoulvant, T; Saadatian-Elahi, M; Lafont, S; Bergeonneau, C; Kassaï, B; Erpeldinger, S; Wright, JM; Gueyffier, F; Cornu, C (2011-07-26). "Effect of intensive glucose lowering treatment on all cause mortality, cardiovascular death, and microvascular events in type 2 diabetes: meta-analysis of randomised controlled trials". The BMJ. 343: d4169. doi:10.1136/bmj.d4169. PMC 3144314. PMID 21791495.
It's not as clear what the rest of the type 1 genes are up to, but researchers are eager to find out. "Even though something accounts for a small part [of the genetic risk], it could have a significant impact," says Stephen Rich, PhD, director of the Center for Public Health Genomics at the University of Virginia School of Medicine. Understanding these genes' role may clue researchers in to less obvious biological pathways involved in type 1 diabetes, and to possible prevention strategies.
Visual impairment and blindness are common sequelae of uncontrolled diabetes. The three most frequently occurring problems involving the eye are diabetic retinopathy, cataracts, and glaucoma. photocoagulation of destructive lesions of the retina with laser beams can be used to delay further progress of pathologic changes and thereby preserve sight in the affected eye.
^ Jump up to: a b c d GBD 2015 Disease and Injury Incidence and Prevalence, Collaborators. (8 October 2016). "Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990–2015: a systematic analysis for the Global Burden of Disease Study 2015". The Lancet. 388 (10053): 1545–1602. doi:10.1016/S0140-6736(16)31678-6. PMC 5055577. PMID 27733282.
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.
Lose Weight: If you are overweight, losing weight can help your body use insulin. In fact, the American Diabetes Association recommends that people with diabetes lose about 7 percent of their body weight, which should improve the way your body uses insulin and reduces insulin resistance. In addition, weight loss can help lower blood pressure, reduce joint pain, increase energy, and reduce sleep apnea and cholesterol. It can also reduce your risk of other diseases, including heart disease.

^ Jump up to: a b c Maruthur, NM; Tseng, E; Hutfless, S; Wilson, LM; Suarez-Cuervo, C; Berger, Z; Chu, Y; Iyoha, E; Segal, JB; Bolen, S (19 April 2016). "Diabetes Medications as Monotherapy or Metformin-Based Combination Therapy for Type 2 Diabetes: A Systematic Review and Meta-analysis". Annals of Internal Medicine. 164 (11): 740–51. doi:10.7326/M15-2650. PMID 27088241.
Diabetic ketoacidosis can be caused by infections, stress, or trauma, all of which may increase insulin requirements. In addition, missing doses of insulin is also an obvious risk factor for developing diabetic ketoacidosis. Urgent treatment of diabetic ketoacidosis involves the intravenous administration of fluid, electrolytes, and insulin, usually in a hospital intensive care unit. Dehydration can be very severe, and it is not unusual to need to replace 6-7 liters of fluid when a person presents in diabetic ketoacidosis. Antibiotics are given for infections. With treatment, abnormal blood sugar levels, ketone production, acidosis, and dehydration can be reversed rapidly, and patients can recover remarkably well.

If you’re getting a good night’s rest but still find yourself so tired you can barely function, it’s definitely worth mentioning to your doctor. Diabetes often wreaks havoc on a person’s normal blood sugar levels, causing fatigue in the process. In later stages, the tissue death associated with untreated diabetes can also limit circulation, meaning oxygenated blood isn’t being effectively transported to your vital organs, making your body work harder and tiring you out along the way.


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."
The patient, physician, nurse, and dietician must carefully evaluate the patient's life style, nutritional needs, and ability to comply with the proposed dietary prescription. There are a variety of meal planning systems that can be used by the patient with diabetes; each has benefits and drawbacks that need to be evaluated in order to maximize compliance. Two of the most frequently used ones are the exchange system (see accompanying table) and the carbohydrate counting system.
With such a surplus of food nowadays, it's easy to overindulge without physical activity, leading to weight gain and, for some people, eventual Type 2 diabetes. "It's a lack of exercise and still eating like you're 20 years old," says Susan M. De Abate, a nurse and certified diabetes educator and team coordinator of the diabetes education program at Sentara Virginia Beach General Hospital.
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]
Dr. May currently works as a fulltime endocrinologist and has been in private practice since 2004. He has a variety of interests, predominantly obesity and diabetes, but also sees patients with osteoporosis, thyroid disorders, men's health disorders, pituitary and adrenal disorders, polycystic ovaries, and disorders of growth. He is a leading member of several obesity and diabetes societies and runs a trial centre for new drugs.
Type 2 diabetes is typically a chronic disease associated with a ten-year-shorter life expectancy.[10] This is partly due to a number of complications with which it is associated, including: two to four times the risk of cardiovascular disease, including ischemic heart disease and stroke; a 20-fold increase in lower limb amputations, and increased rates of hospitalizations.[10] In the developed world, and increasingly elsewhere, type 2 diabetes is the largest cause of nontraumatic blindness and kidney failure.[24] It has also been associated with an increased risk of cognitive dysfunction and dementia through disease processes such as Alzheimer's disease and vascular dementia.[25] Other complications include acanthosis nigricans, sexual dysfunction, and frequent infections.[23]
Environmental factors are important, because even identical twins have only a 30-60% concordance for type 1 diabetes mellitus and because incidence rates vary in genetically similar populations under different living conditions. [25] No single factor has been identified, but infections and diet are considered the 2 most likely environmental candidates.
Some older people cannot control what they eat because someone else is cooking for them—at home or in a nursing home or other institution. When people with diabetes do not do their own cooking, the people who shop and prepare meals for them must also understand the diet that is needed. Older people and their caregivers usually benefit from meeting with a dietitian to develop a healthy, feasible eating plan.
Onset of type 2 diabetes can be delayed or prevented through proper nutrition and regular exercise.[60][61] Intensive lifestyle measures may reduce the risk by over half.[24][62] The benefit of exercise occurs regardless of the person's initial weight or subsequent weight loss.[63] High levels of physical activity reduce the risk of diabetes by about 28%.[64] Evidence for the benefit of dietary changes alone, however, is limited,[65] with some evidence for a diet high in green leafy vegetables[66] and some for limiting the intake of sugary drinks.[32] In those with impaired glucose tolerance, diet and exercise either alone or in combination with metformin or acarbose may decrease the risk of developing diabetes.[24][67] Lifestyle interventions are more effective than metformin.[24] A 2017 review found that, long term, lifestyle changes decreased the risk by 28%, while medication does not reduce risk after withdrawal.[68] While low vitamin D levels are associated with an increased risk of diabetes, correcting the levels by supplementing vitamin D3 does not improve that risk.[69]

nephrogenic diabetes insipidus a rare form caused by failure of the renal tubules to reabsorb water; there is excessive production of antidiuretic hormone but the tubules fail to respond to it. Characteristics include polyuria, extreme thirst, growth retardation, and developmental delay. The condition does not respond to exogenous vasopressin. It may be inherited as an X-linked trait or be acquired as a result of drug therapy or systemic disease.
Although the signs of diabetes can begin to show early, sometimes it takes a person a while to recognize the symptoms. This often makes it seem like signs and symptoms of diabetes appear suddenly. That’s why it’s important to pay attention to your body, rather than simply brushing them off. To that end, here are some type 1 and type 2 diabetes symptoms that you may want to watch out for:

Most cases of diabetes involve many genes, with each being a small contributor to an increased probability of becoming a type 2 diabetic.[10] If one identical twin has diabetes, the chance of the other developing diabetes within his lifetime is greater than 90%, while the rate for nonidentical siblings is 25–50%.[13] As of 2011, more than 36 genes had been found that contribute to the risk of type 2 diabetes.[37] All of these genes together still only account for 10% of the total heritable component of the disease.[37] The TCF7L2 allele, for example, increases the risk of developing diabetes by 1.5 times and is the greatest risk of the common genetic variants.[13] Most of the genes linked to diabetes are involved in beta cell functions.[13]

Research continues on diabetes prevention and improved detection of those at risk for developing diabetes. While the onset of Type I diabetes is unpredictable, the risk of developing Type II diabetes can be reduced by maintaining ideal weight and exercising regularly. The physical and emotional stress of surgery, illness, pregnancy, and alcoholism can increase the risks of diabetes, so maintaining a healthy lifestyle is critical to preventing the onset of Type II diabetes and preventing further complications of the disease.
Because both yeast and bacteria multiply more quickly when blood sugar levels are elevated, women with diabetes are overall at a higher risk of feminine health issues, such as bacterial infections, yeast infections, and vaginal thrush, especially when blood sugar isn't well controlled. And a lack of awareness about having prediabetes or diabetes can make managing blood sugar impossible.
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