There are many types of sugar. Some sugars are simple, and others are complex. Table sugar (sucrose) is made of two simpler sugars called glucose and fructose. Milk sugar (lactose) is made of glucose and a simple sugar called galactose. The carbohydrates in starches, such as bread, pasta, rice, and similar foods, are long chains of different simple sugar molecules. Sucrose, lactose, carbohydrates, and other complex sugars must be broken down into simple sugars by enzymes in the digestive tract before the body can absorb them.
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.
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]

The elderly diabetic person is at increased risk of atrial fibrillation (odds ratio: 1.4 for men and 1.6 for women)232 and at twofold increased risk of thromboembolism from atrial fibrillation.233,234 We can find no subgroup analysis of the major atrial fibrillation trials to examine the benefits of warfarin specifically in older diabetic subjects. It appears that the adverse event rate in diabetic people drops from 8.6 events per 100 patients per year to 2.8 events with warfarin use.234 It is important to check for retinal new vessels when diabetic subjects are placed on warfarin, although the Early Treatment Diabetic Retinopathy Study235 showed no excess vitreous or preretinal hemorrhages in subjects given aspirin for vascular prophylaxis.

Insulin Therapy. Exogenous insulin is given to patients with diabetes mellitus as a supplement to the insufficient amount of endogenous insulin that they produce. In some cases, this must make up for an absolute lack of insulin from the pancreas. Exogenous insulin is available in various types. It must be given by injection, usually subcutaneously, and because it is a potent drug, the dosage must be measured meticulously. Commonly, regular insulin, which is a fast-acting insulin with a short span of action, is mixed with one of the longer-acting insulins and both types are administered in one injection.

Before blood glucose levels rise, the body of a person destined for type 2 becomes resistant to insulin, much as bacteria can become resistant to antibiotics. Insulin is the signal for the muscles, fat, and liver to absorb glucose from the blood. As the body becomes resistant to insulin, the beta cells in the pancreas must pump out more of the hormone to compensate. People with beta cells that can't keep up with insulin resistance develop the high blood glucose of type 2 diabetes.

^ Jump up to: a b 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. 13 (41): 1–190, 215–357, iii–iv. doi:10.3310/hta13410. PMID 19726018.

Can type 2 diabetes be prevented? It is possible to reduce the risk of developing type 2 diabetes, although the underlying risk of type 2 diabetes depends strongly on genetic factors. But there was less type 2 diabetes around some years ago when people had a more active life and didn’t eat a modern Western diet. So it is fair to say that risk of getting type 2 diabetes is based on a genetic predisposition that is aggravated by lifestyle. Type 2 diabetes is associated with obesity, as well as a variety of environmental factors. To lower the risk of developing type 2 diabetes (as well as other diseases), it is highly recommended to exercise often, eat healthily, and maintain a healthy weight. 

Large, population-based studies in China, Finland and USA have recently demonstrated the feasibility of preventing, or delaying, the onset of diabetes in overweight subjects with mild glucose intolerance (IGT). The studies suggest that even moderate reduction in weight and only half an hour of walking each day reduced the incidence of diabetes by more than one half.
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.
Another form of diabetes called gestational diabetes can develop during pregnancy and generally resolves after the baby is delivered. This diabetic condition develops during the second or third trimester of pregnancy in about 2% of pregnancies. In 2004, incidence of gestational diabetes were reported to have increased 35% in 10 years. Children of women with gestational diabetes are more likely to be born prematurely, have hypoglycemia, or have severe jaundice at birth. The condition usually is treated by diet, however, insulin injections may be required. These women who have diabetes during pregnancy are at higher risk for developing Type II diabetes within 5-10 years.
Culturally appropriate education may help people with type 2 diabetes control their blood sugar levels, for up to 24 months.[89] If changes in lifestyle in those with mild diabetes has not resulted in improved blood sugars within six weeks, medications should then be considered.[23] There is not enough evidence to determine if lifestyle interventions affect mortality in those who already have DM2.[62]
Glucose in your body can cause yeast infections. This is because glucose speeds the growth of fungus. There are over-the-counter and prescription medications to treat yeast infections. You can potentially avoid yeast infections by maintaining better control of your blood sugar. Take insulin as prescribed, exercise regularly, reduce your carb intake, choose low-glycemic foods, and monitor your blood sugar.