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.

Diabetes is a chronic condition, and it can last an entire lifetime. The goal of treating diabetes is to keep blood glucose levels as close to a normal range as possible. This prevents the symptoms of diabetes and the long-term complications of the condition. If you've been diagnosed with diabetes, your doctor – working with the members of your diabetes care team – will help you find your target blood glucose levels.
In the sunshine, molecules in the skin are converted to vitamin D. But people stay indoors more these days, which could lead to vitamin D deficiency. Research shows that if mice are deprived of vitamin D, they are more likely to become diabetic. In people, observational studies have also found a correlation between D deficiency and type 1. "If you don't have enough D, then [your immune system] doesn't function like it should," says Chantal Mathieu, MD, PhD, a professor of experimental medicine and endocrinology at Katholieke Universiteit Leuven in Belgium. "Vitamin D is not the cause of type 1 diabetes. [But] if you already have a risk, you don't want to have vitamin D deficiency on board because that's going to be one of the little pushes that pushes you in the wrong direction."

Dr. Erica Oberg, ND, MPH, received a BA in anthropology from the University of Colorado, her doctorate of naturopathic medicine (ND) from Bastyr University, and a masters of public health (MPH) in health services research from the University of Washington. She completed her residency at the Bastyr Center for Natural Health in ambulatory primary care and fellowship training at the Health Promotion Research Center at the University of Washington.

A growing number of people in the U.S. and throughout the world are overweight and more prone to develop Type 2 diabetes, particularly if they have the genetics for it. "Type 2 diabetes can be caused by genetic inheritance, but by far the obesity epidemic has created massive increases in the occurrence of Type 2 diabetes. This is due to the major insulin resistance that is created by obesity," Gage says.
Having diabetes requires life-long treatment and follow-up by health professionals. Diabetes can be linked to damage of the eyes, kidneys and feet. It is also associated with increased risk of strokes, heart attacks and poor blood circulation to the legs. Medical care aims to minimise these risks by controlling diabetes, blood pressure and cholesterol and screening for possible complications caused by the diabetes. 
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.

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]

Type 2 (formerly called 'adult-onset' or 'non insulin-dependent') diabetes results when the body doesn’t produce enough insulin and/or is unable to use insulin properly (this is also referred to as ‘insulin resistance’). This form of diabetes usually occurs in people who are over 40 years of age, overweight, and have a family history of diabetes, although today it is increasingly found in younger people.
The food that people eat provides the body with glucose, which is used by the cells as a source of energy. If insulin isn't available or doesn't work correctly to move glucose from the blood into cells, glucose will stay in the blood. High blood glucose levels are toxic, and cells that don't get glucose are lacking the fuel they need to function properly.
The woman’s weight may also play a role. Changing hormone levels and weight gain are part of a healthy pregnancy, but both changes make it more difficult for the body to keep up with its need for insulin. This may lead to gestational diabetes. As pregnancy progresses, the placenta also produces insulin-blocking hormones, which might result in a woman’s blood-glucose levels becoming elevated if there isn’t enough insulin to counter this effect.

Doctors can also measure the level of a protein, hemoglobin A1C (also called glycosylated or glycolated hemoglobin), in the blood. Hemoglobin is the red, oxygen-carrying substance in red blood cells. When blood is exposed to high blood glucose levels over a period of time, glucose attaches to the hemoglobin and forms glycosylated hemoglobin. The hemoglobin A1C level (reported as the percentage of hemoglobin that is A1C) reflects long-term trends in blood glucose levels rather than rapid changes.

Diabetes mellitus is classified into four broad categories: type 1, type 2, gestational diabetes, and "other specific types".[11] The "other specific types" are a collection of a few dozen individual causes.[11] Diabetes is a more variable disease than once thought and people may have combinations of forms.[37] The term "diabetes", without qualification, usually refers to diabetes mellitus.
Type 2 diabetes mellitus (non–insulin-dependent diabetes mellitus [NIDDM]) is a heterogeneous disorder. Most patients with type 2 diabetes mellitus have insulin resistance, and their beta cells lack the ability to overcome this resistance. [6] Although this form of diabetes was previously uncommon in children, in some countries, 20% or more of new patients with diabetes in childhood and adolescence have type 2 diabetes mellitus, a change associated with increased rates of obesity. Other patients may have inherited disorders of insulin release, leading to maturity onset diabetes of the young (MODY) or congenital diabetes. [7, 8, 9] This topic addresses only type 1 diabetes mellitus. (See Etiology and Epidemiology.)
; 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
observations The onset of type 1 diabetes mellitus is sudden in children. Type 2 diabetes often begins insidiously. Characteristically the course is progressive and includes polyuria, polydipsia, weight loss, polyphagia, hyperglycemia, and glycosuria. The eyes, kidneys, nervous system, skin, and circulatory system may be affected by the long-term complications of either type of diabetes; infections are common; and atherosclerosis often develops. In type 1 diabetes mellitus, when no endogenous insulin is being secreted, ketoacidosis is a constant danger. The diagnosis is confirmed by fasting plasma glucose and history.
Many studies have shown that awareness about the diabetes and its complications is poor among the general population specially in the rural areas6,7. There is an urgent need to create awareness among the population regarding diabetes and about the serious consequences of this chronic disorder. Epidemiological data from India have shown the presence of a number of risk factors which can be easily identified by simple non-invasive risk scores8,9. The major risk factors are listed in Box 1.
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. 

Jump up ^ Imperatore, Giuseppina; Boyle, James P.; Thompson, Theodore J.; Case, Doug; Dabelea, Dana; Hamman, Richard F.; Lawrence, Jean M.; Liese, Angela D.; Liu, Lenna L. (December 2012). "Projections of Type 1 and Type 2 Diabetes Burden in the U.S. Population Aged <20 Years Through 2050". Diabetes Care. 35 (12): 2515–20. doi:10.2337/dc12-0669. ISSN 0149-5992. PMC 3507562. PMID 23173134. Archived from the original on 2016-08-14.

Nerve damage from diabetes is called diabetic neuropathy and is also caused by disease of small blood vessels. In essence, the blood flow to the nerves is limited, leaving the nerves without blood flow, and they get damaged or die as a result (a term known as ischemia). Symptoms of diabetic nerve damage include numbness, burning, and aching of the feet and lower extremities. When the nerve disease causes a complete loss of sensation in the feet, patients may not be aware of injuries to the feet, and fail to properly protect them. Shoes or other protection should be worn as much as possible. Seemingly minor skin injuries should be attended to promptly to avoid serious infections. Because of poor blood circulation, diabetic foot injuries may not heal. Sometimes, minor foot injuries can lead to serious infection, ulcers, and even gangrene, necessitating surgical amputation of toes, feet, and other infected parts.

By the time a person is diagnosed with type 2 diabetes, up to 50% of the beta cells in the pancreas have usually been damaged. In fact, these cells may have been declining for up to 10 years before the diagnosis. Along with raised blood pressure and elevated cholesterol levels, this predisposes the person to arterial damage years before diabetes is diagnosed. So, at the time of diagnosis, the person is already at risk for cardiovascular disease (CVD).
There is no known preventive measure for type 1 diabetes.[2] Type 2 diabetes – which accounts for 85–90% of all cases – can often be prevented or delayed by maintaining a normal body weight, engaging in physical activity, and consuming a healthy diet.[2] Higher levels of physical activity (more than 90 minutes per day) reduce the risk of diabetes by 28%.[71] Dietary changes known to be effective in helping to prevent diabetes include maintaining a diet rich in whole grains and fiber, and choosing good fats, such as the polyunsaturated fats found in nuts, vegetable oils, and fish.[72] Limiting sugary beverages and eating less red meat and other sources of saturated fat can also help prevent diabetes.[72] Tobacco smoking is also associated with an increased risk of diabetes and its complications, so smoking cessation can be an important preventive measure as well.[73]
When your blood sugar is out of whack, you just don’t feel well, says Cypress, and might become more short-tempered. In fact, high blood sugar can mimic depression-like symptoms. “You feel very tired, you don’t feel like doing anything, you don’t want to go out, you just want to sleep,” Cypress says. She’ll see patients who think they need to be treated for depression, but then experience mood improvement after their blood sugar normalizes.
^ 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.
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]
Older people may have a difficult time adding exercise to their daily life, particularly if they have not been active or if they have a disorder that limits their movement, such as arthritis. However, they may be able to add exercise to their usual routine. For example, they can walk instead of drive or climb the stairs instead of take the elevator. Also, many community organizations offer exercise programs designed for older people.

In general, women live longer than men do because they have a lower risk of heart disease, but when women develop diabetes, their risk for heart disease skyrockets, and death by heart failure is more likely in women than in men. Another study also found that in people with diabetes, heart attacks are more often fatal for women than they are for men. Other examples of how diabetes affects women differently than men are:

*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For information on a given medication, check our Drug Information database. For more information on brand names, speak with your doctor or pharmacist.
Jump up ^ Imperatore, Giuseppina; Boyle, James P.; Thompson, Theodore J.; Case, Doug; Dabelea, Dana; Hamman, Richard F.; Lawrence, Jean M.; Liese, Angela D.; Liu, Lenna L. (December 2012). "Projections of Type 1 and Type 2 Diabetes Burden in the U.S. Population Aged <20 Years Through 2050". Diabetes Care. 35 (12): 2515–20. doi:10.2337/dc12-0669. ISSN 0149-5992. PMC 3507562. PMID 23173134. Archived from the original on 2016-08-14.

Jump up ^ Attridge, Madeleine; Creamer, John; Ramsden, Michael; Cannings-John, Rebecca; Hawthorne, Kamila (2014-09-04). "Culturally appropriate health education for people in ethnic minority groups with type 2 diabetes mellitus". Cochrane Database of Systematic Reviews (9): CD006424. doi:10.1002/14651858.CD006424.pub3. ISSN 1469-493X. PMID 25188210.
A type 2 diabetes diet or a type 2 diabetic diet is important for blood sugar (glucose) control in people with diabetes to prevent complications of diabetes. There are a variety of type 2 diabetes diet eating plans such as the Mediterranean diet, Paleo diet, ADA Diabetes Diet, and vegetarian diets.Learn about low and high glycemic index foods, what foods to eat, and what foods to avoid if you have type 2 diabetes.