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.

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]
Excess glucose in the blood can damage small blood vessels in the nerves causing a tingling sensation or pain in the fingers, toes and limbs. Nerves that lie outside of the central nervous system may also be damaged, which is referred to as peripheral neuropathy. If nerves of the gastrointestinal tract are affected, this may cause vomiting, constipation and diarrhea.

After a diagnosis of diabetes mellitus has been made, and treatment with insulin therapy has begun, a so-called ‘honeymoon stage’ may develop. This stage is characterised by a reduction in insulin requirements which may last from weeks to months. Some patients may require no insulin at all. This stage is always transient (short-lasting) and is due to production of insulin by the remaining surviving pancreatic beta cells. Eventually, these cells will be destroyed by the on-going auto-immune process, and the patient will be dependent on exogenous (artificial) insulin.

“I don’t think that anybody has put their finger on what the true cause of diabetes is, or that we’re going to find a single cause,” Grieger says. So if you’ve been diagnosed with prediabetes or have other risk factors for the disease, avoiding any one food group entirely — even sugar — won’t completely offset your risk. Rather, it’s important to prioritize proper nutrition, exercise regularly, and maintain a healthy weight — all steps the American Diabetes Association recommends for preventing type 2 diabetes.
Low blood sugar (hypoglycemia). If your blood sugar level drops below your target range, it's known as low blood sugar (hypoglycemia). Your blood sugar level can drop for many reasons, including skipping a meal, inadvertently taking more medication than usual or getting more physical activity than normal. Low blood sugar is most likely if you take glucose-lowering medications that promote the secretion of insulin or if you're taking insulin.

Type 2 diabetes is a preventable disease that affects more than 9 percent of the U.S. population, or about 29 million people. According to the Centers for Disease Control and Prevention, more than a quarter — some 8 million people — remain undiagnosed. With complications including nerve damage, kidney damage, poor blood circulation, and even death, it’s important for us all to know the early signs of type 2 diabetes.
Diabetes is a serious and costly disease which is becoming increasingly common, especially in developing countries and disadvantaged minorities. However, there are ways of preventing it and/or controlling its progress. Public and professional awareness of the risk factors for, and symptoms of diabetes are an important step towards its prevention and control.
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.
^ 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.
Risk factors for type 2 diabetes include obesity, high cholesterol, high blood pressure, and physical inactivity. The risk of developing type 2 diabetes also increases as people grow older. People who are over 40 and overweight are more likely to develop type 2 diabetes, although the incidence of this type of diabetes in adolescents is growing. Diabetes is more common among Native Americans, African Americans, Hispanic Americans and Asian Americans/Pacific Islanders. Also, people who develop diabetes while pregnant (a condition called gestational diabetes) are more likely to develop type 2 diabetes later in life.
Is type 2 diabetes serious? Type 2 diabetes is not a death sentence, but it is a very serious disease that demands attention and careful monitoring. There is no such thing as ‘mild’ diabetes. Elevated glucose levels can damage the nervous system, blood vessels, eyes, heart, and kidneys. These complications really impact quality of life (through blindness, amputations, dialysis etc). They also significantly increase the chance of a stroke or heart attack. Managing blood glucose levels immediately, along with other health risk factors (e.g., cholesterol, blood pressure, weight), is necessary for preventing these complications. Losing even a small amount of weight and keeping it off can also improve glucose control as well as have other clinical benefits (read more tips on managing diet and exercise below for more on weight loss). Keep in mind that better diabetes management also has benefits in the here and now – mood and energy levels are adversely affected when your glucose levels are high. 
Poor vision, limited manual dexterity due to arthritis, tremor, or stroke, or other physical limitations may make monitoring blood glucose levels more difficult for older people. However, special monitors are available. Some have large numerical displays that are easier to read. Some provide audible instructions and results. Some monitors read blood glucose levels through the skin and do not require a blood sample. People can consult a diabetes educator to determine which meter is most appropriate.
While discovering you have diabetes can be a terrifying prospect, the sooner you’re treated, the more manageable your condition will be. In fact, a review of research published in the American Diabetes Association journal Diabetes Care reveals that early treatment with insulin can help patients with type 2 diabetes manage their blood sugar better and gain less weight than those who start treatment later.
Indigestion (dyspepsia) can be caused by diseases or conditions that involve the gastrointestinal (GI) tract, and also by some diseases and conditions that do not involve the GI tract. Indigestion can be a chronic condition in which the symptoms fluctuate infrequency and intensity. Signs and symptoms that accompany indigestion include pain in the chest, upper abdominal pain, belching, nausea, bloating, abdominal distention, feeling full after eating only a small portion of food, and rarely, vomiting.
It is especially important that persons with diabetes who are taking insulin not skip meals; they must also be sure to eat the prescribed amounts at the prescribed times during the day. Since the insulin-dependent diabetic needs to match food consumption to the available insulin, it is advantageous to increase the number of daily feedings by adding snacks between meals and at bedtime.
At the same time that the body is trying to get rid of glucose from the blood, the cells are starving for glucose and sending signals to the body to eat more food, thus making patients extremely hungry. To provide energy for the starving cells, the body also tries to convert fats and proteins to glucose. The breakdown of fats and proteins for energy causes acid compounds called ketones to form in the blood. Ketones also will be excreted in the urine. As ketones build up in the blood, a condition called ketoacidosis can occur. This condition can be life threatening if left untreated, leading to coma and death.

Jump up ^ Cheng J, Zhang W, Zhang X, Han F, Li X, He X, Li Q, Chen J (May 2014). "Effect of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers on all-cause mortality, cardiovascular deaths, and cardiovascular events in patients with diabetes mellitus: a meta-analysis". JAMA Internal Medicine. 174 (5): 773–85. doi:10.1001/jamainternmed.2014.348. PMID 24687000.
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.
Feeling famished all the time? Your body could be trying to tell you that something’s up with your blood sugar. Many people with diabetes experience extreme hunger when their condition is unmanaged, thanks to high blood sugar levels. When your body can’t effectively convert the sugar in your blood into usable energy, this may leave you pining for every sandwich or sweet you see. And if you’re looking for a filling snack that won’t put your health at risk, enjoy one of the 25 Best and Worst Low-Sugar Protein Bars!

Random blood sugar test. A blood sample will be taken at a random time. Blood sugar values are expressed in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). Regardless of when you last ate, a random blood sugar level of 200 mg/dL (11.1 mmol/L) or higher suggests diabetes, especially when coupled with any of the signs and symptoms of diabetes, such as frequent urination and extreme thirst.
"Secondary" diabetes refers to elevated blood sugar levels from another medical condition. Secondary diabetes may develop when the pancreatic tissue responsible for the production of insulin is destroyed by disease, such as chronic pancreatitis (inflammation of the pancreas by toxins like excessive alcohol), trauma, or surgical removal of the pancreas.
Exercise is very important if you have this health condition. Exercise makes cells more insulin sensitive, pulling glucose out of the blood. This brings down blood sugar, and more importantly, gives you better energy because the glucose is being transferred to the cells. Any type of exercise will do this, but extra benefit is gained when the activity helps build muscle, such as weight training or using resistance bands. The benefits of exercise on blood sugar last about 48-72 hours, so it is important for you to be physically active almost every day.
Type 2 diabetes: Type 2 diabetes affects the way the body uses insulin. While the body still makes insulin, unlike in type I, the cells in the body do not respond to it as effectively as they once did. This is the most common type of diabetes, according to the National Institute of Diabetes and Digestive and Kidney Diseases, and it has strong links with obesity.
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.
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.
In people with type 1 diabetes, the symptoms often begin abruptly and dramatically. A serious condition called diabetic ketoacidosis, a complication in which the body produces excess acid, may quickly develop. In addition to the usual diabetes symptoms of excessive thirst and urination, the initial symptoms of diabetic ketoacidosis also include nausea, vomiting, fatigue, and—particularly in children—abdominal pain. Breathing tends to become deep and rapid as the body attempts to correct the blood’s acidity (see Acidosis), and the breath smells fruity and like nail polish remover. Without treatment, diabetic ketoacidosis can progress to coma and death, sometimes very quickly.
5. Signs and symptoms ofhyperglycemiaandhypoglycemia, and measures to take when they occur. (See accompanying table.) It is important for patients to become familiar with specific signs that are unique to themselves. Each person responds differently and may exhibit symptoms different from those experienced by others. It should be noted that the signs and symptoms may vary even within one individual. Thus it is vital that the person understand all reactions that could occur. When there is doubt, a simple blood glucose reading will determine the actions that should be taken.

Glycated hemoglobin (A1C) test. This blood test indicates your average blood sugar level for the past two to three months. It measures the percentage of blood sugar attached to hemoglobin, the oxygen-carrying protein in red blood cells. The higher your blood sugar levels, the more hemoglobin you'll have with sugar attached. An A1C level of 6.5 percent or higher on two separate tests indicates you have diabetes. A result between 5.7 and 6.4 percent is considered prediabetes, which indicates a high risk of developing diabetes. Normal levels are below 5.7 percent.
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Low blood sugar (hypoglycemia), is common in people with type 1 and type 2 DM. Most cases are mild and are not considered medical emergencies. Effects can range from feelings of unease, sweating, trembling, and increased appetite in mild cases to more serious effects such as confusion, changes in behavior such as aggressiveness, seizures, unconsciousness, and (rarely) permanent brain damage or death in severe cases.[24][25] Moderately low blood sugar may easily be mistaken for drunkenness;[26] rapid breathing and sweating, cold, pale skin are characteristic of low blood sugar but not definitive.[27] Mild to moderate cases are self-treated by eating or drinking something high in sugar. Severe cases can lead to unconsciousness and must be treated with intravenous glucose or injections with glucagon.[28]
Type 2 diabetes: Type 2 diabetes affects the way the body uses insulin. While the body still makes insulin, unlike in type I, the cells in the body do not respond to it as effectively as they once did. This is the most common type of diabetes, according to the National Institute of Diabetes and Digestive and Kidney Diseases, and it has strong links with obesity.
The progression of nephropathy in patients can be significantly slowed by controlling high blood pressure, and by aggressively treating high blood sugar levels. Angiotensin converting enzyme inhibitors (ACE inhibitors) or angiotensin receptor blockers (ARBs) used in treating high blood pressure may also benefit kidney disease in patients with diabetes.
The World Health Organization recommends testing those groups at high risk[54] and in 2014 the USPSTF is considering a similar recommendation.[58] High-risk groups in the United States include: those over 45 years old; those with a first degree relative with diabetes; some ethnic groups, including Hispanics, African-Americans, and Native-Americans; a history of gestational diabetes; polycystic ovary syndrome; excess weight; and conditions associated with metabolic syndrome.[23] The American Diabetes Association recommends screening those who have a BMI over 25 (in people of Asian descent screening is recommended for a BMI over 23).[59]
One particular type of sugar that has attracted a lot of negative attention is high-fructose corn syrup (HFCS) — and for good reason, as multiple studies suggest HFCS can influence diabetes risk. Some research in people who are overweight and obese, for example, suggests regularly consuming drinks sweetened with either fructose, a byproduct of HFCS, or glucose can lead to weight gain, and drinks with fructose in particular may reduce insulin sensitivity and spike blood sugar levels.

Diabetes mellitus occurs throughout the world but is more common (especially type 2) in more developed countries. The greatest increase in rates has however been seen in low- and middle-income countries,[101] where more than 80% of diabetic deaths occur.[105] The fastest prevalence increase is expected to occur in Asia and Africa, where most people with diabetes will probably live in 2030.[106] The increase in rates in developing countries follows the trend of urbanization and lifestyle changes, including increasingly sedentary lifestyles, less physically demanding work and the global nutrition transition, marked by increased intake of foods that are high energy-dense but nutrient-poor (often high in sugar and saturated fats, sometimes referred to as the "Western-style" diet).[101][106] The global prevalence of diabetes might increase by 55% between 2013 and 2035.[101]
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. 

Diabetes is suspected based on symptoms. Urine tests and blood tests can be used to confirm a diagnose of diabetes based on the amount of glucose found. Urine can also detect ketones and protein in the urine that may help diagnose diabetes and assess how well the kidneys are functioning. These tests also can be used to monitor the disease once the patient is on a standardized diet, oral medications, or insulin.
Then, once you do have an injury, uncontrolled diabetes can make it harder for your body to heal. “High blood sugars provide a good environment for bacteria to grow,” she says. That's because diabetes is also often accompanied by high blood pressure and high cholesterol, and the resulting plaque buildup can narrow blood vessels, reducing blood supply and leading to slow healing.