diabetes mel´litus a broadly applied term used to denote a complex group of syndromes that have in common a disturbance in the oxidation and utilization of glucose, which may be secondary to a malfunction of the beta cells of the pancreas, whose function is the production and release of insulin. Because insulin is involved in the metabolism of carbohydrates, proteins, and fats, diabetes is not limited to a disturbance of glucose homeostasis alone. Insulin resistance may also sometimes play a role in the etiology of diabetes. 
People with diabetes either don't make insulin or their body's cells no longer are able to use the insulin, leading to high blood sugars. By definition, diabetes is having a blood glucose level of greater than or equal to126 milligrams per deciliter (mg/dL) after an 8-hour fast (not eating anything), or by having a non-fasting glucose level greater than or equal to 200 mg/dL along with symptoms of diabetes, or a glucose level of greater than or equal to 200 mg/dL on a 2-hour glucose tolerance test, or an A1C greater than or equal to 6.5%. Unless the person is having obvious symptoms of diabetes or is in a diabetic crisis, the diagnosis must be confirmed with a repeat test.
Type 1 diabetes is partly inherited, with multiple genes, including certain HLA genotypes, known to influence the risk of diabetes. In genetically susceptible people, the onset of diabetes can be triggered by one or more environmental factors,[41] such as a viral infection or diet. Several viruses have been implicated, but to date there is no stringent evidence to support this hypothesis in humans.[41][42] Among dietary factors, data suggest that gliadin (a protein present in gluten) may play a role in the development of type 1 diabetes, but the mechanism is not fully understood.[43][44]
Blood glucose levels: persistently elevated blood sugar levels are diagnostic of diabetes mellitus. A specific test called a glucose tolerance test (GTT) may be performed. For this you need to be fasted and will be given a sugary drink. Your glucose level will then be measured at one and two hours after the doseto determine how welll your body copes with glucose.
Diabetes can occur temporarily during pregnancy, and reports suggest that it occurs in 2% to 10% of all pregnancies. Significant hormonal changes during pregnancy can lead to blood sugar elevation in genetically predisposed individuals. Blood sugar elevation during pregnancy is called gestational diabetes. Gestational diabetes usually resolves once the baby is born. However, 35% to 60% of women with gestational diabetes will eventually develop type 2 diabetes over the next 10 to 20 years, especially in those who require insulin during pregnancy and those who remain overweight after their delivery. Women with gestational diabetes are usually asked to undergo an oral glucose tolerance test about six weeks after giving birth to determine if their diabetes has persisted beyond the pregnancy, or if any evidence (such as impaired glucose tolerance) is present that may be a clue to a risk for developing diabetes.
Diabetes mellitus, or simply diabetes, is a group of diseases in which a person does not produce enough insulin, or because it does not respond to the insulin that is produced. Insulin is a hormone that controls the amount of glucose (sugar) in the blood. Diabetes leads to high blood sugar levels, which can lead to damage of blood vessels, organs, and nerves.

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.

Diabetes mellitus is not a single disorder but a heterogeneous group of disorders. All forms are characterized by hyperglycemia and disturbances of carbohydrate, fat, and protein metabolism which are associated with absolute or relative deficiencies of insulin action and/or insulin secretion. The World Health Organization (WHO) developed a now widely accepted classification of the disorder, largely based on clinical characteristics (see Table 1, WHO, 1985).
Type 2 diabetes is mainly caused by insulin resistance. This means no matter how much or how little insulin is made, the body can't use it as well as it should. As a result, glucose can't be moved from the blood into cells. Over time, the excess sugar in the blood gradually poisons the pancreas causing it to make less insulin and making it even more difficult to keep blood glucose under control.
Although this newfound knowledge on sugar, and specifically added sugar, may prompt you to ditch the soda, juice, and processed foods, be mindful of the other factors that can similarly influence your risk for type 2 diabetes. Obesity, a family history of diabetes, a personal history of heart disease, and depression, for instance, are other predictors for the disease, according to the NIH.
Diabetes Forum App Find support, ask questions and share your experiences with 281,823 members of the diabetes community. Recipe App Delicious diabetes recipes, updated every Monday. Filter recipes by carbs, calories and time to cook. Low Carb Program Join 250,000 people on the award-winning education program for people with type 2 diabetes, prediabetes and obesity. Hypo Awareness Program The first comprehensive, free and open to all online step-by-step guide to improving hypo awareness. DiabetesPA Your diabetes personal assistant. Monitor every aspect of your diabetes. Simple, practical, free.
^ Jump up to: a b Petzold A, Solimena M, Knoch KP (October 2015). "Mechanisms of Beta Cell Dysfunction Associated With Viral Infection". Current Diabetes Reports (Review). 15 (10): 73. doi:10.1007/s11892-015-0654-x. PMC 4539350. PMID 26280364. So far, none of the hypotheses accounting for virus-induced beta cell autoimmunity has been supported by stringent evidence in humans, and the involvement of several mechanisms rather than just one is also plausible.
Autonomic changes involving cardiovascular control (eg, heart rate, postural responses) have been described in as many as 40% of children with diabetes. Cardiovascular control changes become more likely with increasing duration and worsening control. [18] In a study by 253 patients with type 1 diabetes (mean age at baseline 14.4 y), Cho et al reported that the prevalence of cardiac autonomic dysfunction increases in association with higher body mass index and central adiposity. [19]
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.