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.)

To measure blood glucose levels, a blood sample is usually taken after people have fasted overnight. However, it is possible to take blood samples after people have eaten. Some elevation of blood glucose levels after eating is normal, but even after a meal the levels should not be very high. Fasting blood glucose levels should never be higher than 125 mg/dL. Even after eating, blood glucose levels should not be higher than 199 mg/dL.
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]
In animals, diabetes is most commonly encountered in dogs and cats. Middle-aged animals are most commonly affected. Female dogs are twice as likely to be affected as males, while according to some sources, male cats are also more prone than females. In both species, all breeds may be affected, but some small dog breeds are particularly likely to develop diabetes, such as Miniature Poodles.[123]
They may need to take medications in order to keep glucose levels within a healthy range. Medications for type 2 diabetes are usually taken by mouth in the form of tablets and should always be taken around meal times and as prescribed by the doctor. However, if blood glucose is not controlled by oral medications, a doctor may recommend insulin injections.
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.
a chronic metabolic disorder in which the use of carbohydrate is impaired and that of lipid and protein is enhanced. It is caused by an absolute or relative deficiency of insulin and is characterized, in more severe cases, by chronic hyperglycemia, glycosuria, water and electrolyte loss, ketoacidosis, and coma. Long-term complications include neuropathy, retinopathy, nephropathy, generalized degenerative changes in large and small blood vessels, and increased susceptibility to infection.
Most people with diabetes should keep a record of their blood glucose levels and report them to their doctor or nurse for advice in adjusting the dose of insulin or the oral antihyperglycemic drug. Many people can learn to adjust the insulin dose on their own as necessary. Some people who have mild or early type 2 diabetes that is well-controlled with one or two drugs may be able to monitor their fingerstick glucose levels relatively infrequently.
A neck lump or nodule is the most common symptom of thyroid cancer. You may feel a lump, notice one side of your neck appears to be different, or your doctor may find it during a routine examination. If the tumor is large, it may cause neck or facial pain, shortness of breath, difficulty swallowing, cough unrelated to a cold, hoarseness or voice change.

We give you special kudos for managing your condition, as it is not always easy. If you've had diabetes for a long time, it's normal to burn out sometimes. You may get tired of your day to day tasks, such as counting carbohydrates or measuring your blood sugar. Lean on a loved one or a friend for support, or consider talking to someone else who has diabetes who can provide, perhaps, an even more understanding ear or ideas that can help you.
Alternatively, if you hit it really hard for 20 minutes or so, you may never enter the fat burning phase of exercise. Consequently, your body becomes more efficient at storing sugar (in the form of glycogen) in your liver and muscles, where it is needed, as glycogen is the muscles’ primary fuel source. If your body is efficient at storing and using of glycogen, it means that it is not storing fat.
Manage mild hypoglycemia by giving rapidly absorbed oral carbohydrate or glucose; for a comatose patient, administer an intramuscular injection of the hormone glucagon, which stimulates the release of liver glycogen and releases glucose into the circulation. Where appropriate, an alternative therapy is intravenous glucose (preferably no more than a 10% glucose solution). All treatments for hypoglycemia provide recovery in approximately 10 minutes. (See Treatment.)
Patients who suffer from diabetes have a lifelong struggle to attain and maintain blood glucose levels as close to the normal range as possible. With appropriate blood sugar control, the risk of both microvascular (small blood vessel) and neuropathic (nerve) complications is decreased markedly. Additionally, if hypertension (high blood pressure) and hyperlipidemia (high cholesterol) are treated promptly and aggressively, the risk of cardiovascular complications should decrease as well.

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.
Jump up ^ McBrien, K; Rabi, DM; Campbell, N; Barnieh, L; Clement, F; Hemmelgarn, BR; Tonelli, M; Leiter, LA; Klarenbach, SW; Manns, BJ (6 August 2012). "Intensive and Standard Blood Pressure Targets in Patients With Type 2 Diabetes Mellitus: Systematic Review and Meta-analysis". Archives of Internal Medicine. 172 (17): 1–8. doi:10.1001/archinternmed.2012.3147. PMID 22868819.

With gestational diabetes, risks to the unborn baby are even greater than risks to the mother. Risks to the baby include abnormal weight gain before birth, breathing problems at birth, and higher obesity and diabetes risk later in life. Risks to the mother include needing a cesarean section due to an overly large baby, as well as damage to heart, kidney, nerves, and eye.
According to the National Institutes of Health, the reported rate of gestational diabetes is between 2% to 10% of pregnancies. Gestational diabetes usually resolves itself after pregnancy. Having gestational diabetes does, however, put mothers at risk for developing type 2 diabetes later in life. Up to 10% of women with gestational diabetes develop type 2 diabetes. It can occur anywhere from a few weeks after delivery to months or years later.
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.

Type 1 diabetes mellitus is predominantly a disease of the young, usually developing before 20 years of age. Overall, type I DM makes up approximately 15% of all cases of diabetes. It develops in approximately 1 in 600 children and is one of the most common chronic diseases in children. The incidence is relatively low for children under the age of 5, increases between 5 and 15, and then tapers off.


The signs and symptoms of diabetes are disregarded by many because of the chronic progression of the disease. People do not consider this as a serious problem because unlike many other diseases the consequences of hyperglycaemia are not manifested immediately. People are not aware that damage can start several years before symptoms become noticeable. This is unfortunate because recognition of early symptoms can help to get the disease under control immediately and to prevent vascular complications.

Your body is like a car—it needs fuel to function. Its primary source of fuel is glucose (sugar), which is gained from foods that contain carbohydrates that get broken down. Insulin, a hormone produced by the pancreas, takes sugar from your blood to your cells to use for energy. However, when you have diabetes, either your pancreas isn't making enough insulin or the insulin that your body is making isn't being used the way it's supposed to be, typically because the cells become resistant to it.
Jump up ^ Pignone M, Alberts MJ, Colwell JA, Cushman M, Inzucchi SE, Mukherjee D, Rosenson RS, Williams CD, Wilson PW, Kirkman MS (June 2010). "Aspirin for primary prevention of cardiovascular events in people with diabetes: a position statement of the American Diabetes Association, a scientific statement of the American Heart Association, and an expert consensus document of the American College of Cardiology Foundation". Diabetes Care. 33 (6): 1395–402. doi:10.2337/dc10-0555. PMC 2875463. PMID 20508233.
Sugary breath isn’t as sweet as it seems.  Diabetics often notice that they’ve developed sweet or nail-polish-like breath before they’re diagnosed. However, if you’re dealing with this strange symptom, time is of the essence. Sweet breath is often a sign of diabetic ketoacidosis, a condition in which your body can’t effectively convert glucose into energy, keeping your blood sugar at dangerous—potentially fatal—levels if untreated.
Diabetes mellitus, or as it's more commonly known diabetes, is a disease characterized by an excess of blood glucose, or blood sugar, which builds up in the bloodstream when your body isn't able to adequately process the sugar in food. High blood sugar is an abnormal state for the body and creates specific symptoms and possible long-term health problems if blood sugar is not managed well.

The problem with sweetened drinks is that, due to their liquid form, they’re among the fastest simple carbs to be digested in the body, causing blood sugar levels to spike even more than a simple carb in solid-food form would. Research supports this idea: A review published in November 2010 in the journal Diabetes Care suggested adding only one serving of a sweetened beverage to your diet may increase your risk for type 2 diabetes by 15 percent.
Recognizing the symptoms of Type 1 diabetes is critical. Although Type 1 develops gradually, as the body’s insulin production decreases, blood glucose levels can become dangerously high once insulin production is outpaced. Symptoms may develop rapidly and can be mistaken for other illnesses such as the flu and a delayed diagnosis can have serious consequences.

Type 2 diabetes was also previously referred to as non-insulin dependent diabetes mellitus (NIDDM), or adult-onset diabetes mellitus (AODM). In type 2 diabetes, patients can still produce insulin, but do so relatively inadequately for their body's needs, particularly in the face of insulin resistance as discussed above. In many cases this actually means the pancreas produces larger than normal quantities of insulin. A major feature of type 2 diabetes is a lack of sensitivity to insulin by the cells of the body (particularly fat and muscle cells).
Jump up ^ Ahlqvist, Emma; Storm, Petter; Käräjämäki, Annemari; Martinell, Mats; Dorkhan, Mozhgan; Carlsson, Annelie; Vikman, Petter; Prasad, Rashmi B; Aly, Dina Mansour (2018). "Novel subgroups of adult-onset diabetes and their association with outcomes: a data-driven cluster analysis of six variables". The Lancet Diabetes & Endocrinology. 0 (5): 361–369. doi:10.1016/S2213-8587(18)30051-2. ISSN 2213-8587. PMID 29503172.
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]

Healthy lifestyle choices can help you prevent type 2 diabetes. Even if you have diabetes in your family, diet and exercise can help you prevent the disease. If you've already received a diagnosis of diabetes, you can use healthy lifestyle choices to help prevent complications. And if you have prediabetes, lifestyle changes can slow or halt the progression from prediabetes to diabetes.


Insulin is a hormone made by your pancreas that acts like a key to let blood sugar into the cells in your body for use as energy. If you have type 2 diabetes, cells don’t respond normally to insulin; this is called insulin resistance. Your pancreas makes more insulin to try to get cells to respond. Eventually your pancreas can’t keep up, and your blood sugar rises, setting the stage for prediabetes and type 2 diabetes. High blood sugar is damaging to the body and can cause other serious health problems, such as heart disease, vision loss, and kidney disease.

Prediabetes is a condition in which blood glucose levels are too high to be considered normal but not high enough to be labeled diabetes. People have prediabetes if their fasting blood glucose level is between 100 mg/dL and 125 mg/dL or if their blood glucose level 2 hours after a glucose tolerance test is between 140 mg/dL and 199 mg/dL. Prediabetes carries a higher risk of future diabetes as well as heart disease. Decreasing body weight by 5 to 10% through diet and exercise can significantly reduce the risk of developing future diabetes.
When you have Type 2 diabetes, you may start out with something called insulin resistance. This means your cells do not respond well to the insulin you are making. "Insulin levels may be quite high, especially in the early stages of the disease. Eventually, your pancreas may not be able to keep up, and insulin secretion goes down," Rettinger explains. Insulin resistance becomes more common as you put on more weight, especially weight around your belly.
Some risks of the keto diet include low blood sugar, negative medication interactions, and nutrient deficiencies. (People who should avoid the keto diet include those with kidney damage or disease, women who are pregnant or breast-feeding, and those with or at a heightened risk for heart disease due to high blood pressure, high cholesterol, or family history. (40)
Supporting evidence for Shulman's theory comes from observations about a rare genetic illness called lipodystrophy. People with lipodystrophy can't make fat tissue, which is where fat should properly be stored. These thin people also develop severe insulin resistance and type 2 diabetes. "They have fat stored in places it doesn't belong," like the liver and muscles, says Shulman. "When we treat them . . . we melt the fat away, reversing insulin resistance and type 2 diabetes." Shulman's theory also suggests why some people who carry extra fat don't get type 2. "There are some individuals who store fat [under the skin] who have relatively normal insulin sensitivity, a so-called fit fat individual," he says. Because of the way their bodies store fat, he believes, they don't get diabetes.

FIGURE 19-1 ■. This figure shows the hyperbolic relationship of insulin resistance and beta cell function. On the y-axis is beta cell function as reflected in the first-phase insulin response during intravenous (IV) glucose infusion; on the x-axis is insulin sensitivity and its mirror image resistance. In a subject with normal glucose tolerance (NGT) and beta-cell reserve, an increase in insulin resistance results in increased insulin release and normal glucose tolerance. In an individual for whom the capacity to increase insulin release is compromised, increasing insulin resistance with partial or no beta-cell compensation results in progression from normal glucose tolerance, to impaired glucose tolerance (IGT), and finally to diabetes (T2D). Differences between these categories are small at high insulin sensitivity, which may be maintained by weight reduction, exercise, and certain drugs. At a critical degree of insulin resistance, due to obesity or other listed factors, only a further small increment in resistance requires a large increase in insulin output. Those that can increase insulin secretion to this extent retain normal glucose tolerance; those who cannot achieve this degree of insulin secretion (e.g., due to a mild defect in genes regulating insulin synthesis, insulin secretion, insulin action, or an ongoing immune destruction of beta cells) now unmask varying degrees of carbohydrate intolerance. The product of insulin sensitivity (the reciprocal of insulin resistance) and acute insulin response (a measurement beta-cell function) has been called the “disposition index.” This index remains constant in an individual with normal beta cell compensation in response to changes in insulin resistance. IGT, impaired glucose tolerance; NGT, normal glucose tolerance; T2D, type 2 diabetes.
There are many complications of diabetes. Knowing and understanding the signs of these complications is important. If caught early, some of these complications can be treated and prevented from getting worse. The best way to prevent complications of diabetes is to keep your blood sugars in good control. High glucose levels produce changes in the blood vessels themselves, as well as in blood cells (primarily erythrocytes) that impair blood flow to various organs.

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
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