In the exchange system, foods are divided into six food groups (starch, meat, vegetable, fruit, milk, and fat) and the patient is taught to select items from each food group as ordered. Items in each group may be exchanged for each other in specified portions. The patient should avoid concentrated sweets and should increase fiber in the diet. Special dietetic foods are not necessary. Patient teaching should emphasize that a diabetic diet is a healthy diet that all members of the family can follow.
When you have diabetes, your body becomes less efficient at breaking food down into sugar, so you have more sugar sitting in your bloodstream, says Dobbins. “Your body gets rid of it by flushing it out in the urine.” So going to the bathroom a lot could be one of the diabetes symptoms you’re missing. Most patients aren’t necessarily aware of how often they use the bathroom, says Dr. Cypess. “When we ask about it, we often hear, ‘Oh yeah, I guess I’m going more often than I used to,’” he says. But one red flag is whether the need to urinate keeps you up at night. Once or twice might be normal, but if it’s affecting your ability to sleep, that could be a diabetes symptom to pay attention to. Make sure you know these diabetes myths that could sabotage your health.
No single environmental trigger has been identified as causing diabetes mellitus, however both infectious agents and dietary factors are thought to be important. Various viruses have been implicated in the development of type I DM. They may act by initiating or modifying the autoimmune process. In particular, the rubella virus and coxsackie viruses have been closely studied. In particular, congenital rubella infection has shown direct relationships with the development of type 1 diabetes mellitus. This is presumably due to the virus (or antibodies against it) damaging the beta cells of the pancreas. Some research has looked at dietary factors that may be associated with type 1 diabetes. In particular, cow’s milk proteins (such as bovine serum albumin) which may have some similarities to pancreatic islet cell markers may be able to trigger the autoimmune process. Other chemicals including nitrosamines have been identified as causes of diabetes mellitus in animal models, but not in humans.

Taking the drugs used to treat diabetes, particularly insulin, may be difficult for some older people. For those with vision problems or other problems that make accurately filling a syringe difficult, a caregiver can prepare the syringes ahead of time and store them in the refrigerator. People whose insulin dose is stable may purchase pre-filled syringes. Prefilled insulin pen devices may be easier for people with physical limitations. Some of these devices have large numbers and easy-to-turn dials.


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.
Merck & Co., Inc., Kenilworth, NJ, USA is a global healthcare leader working to help the world be well. From developing new therapies that treat and prevent disease to helping people in need, we are committed to improving health and well-being around the world. The Merck Manual was first published in 1899 as a service to the community. The legacy of this great resource continues as the Merck Manual in the US and Canada and the MSD Manual outside of North America. Learn more about our commitment to Global Medical Knowledge.

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.


Type 1 diabetes in pediatric patients has been linked to changes in cognition and brain structure, with a study by Siller et al finding lower volume in the left temporal-parietal-occipital cortex in young patients with type 1 diabetes than in controls. The study also indicated that in pediatric patients, higher severity of type 1 diabetes presentation correlates with greater structural differences in the brain at about 3 months following diagnosis. The investigators found that among study patients with type 1 diabetes, an association existed between the presence of diabetic ketoacidosis at presentation and reduced radial, axial, and mean diffusivity in the major white matter tracts on magnetic resonance imaging (MRI). In those with higher glycated hemoglobin (HbA1c) levels, hippocampal, thalamic, and cerebellar white matter volumes were lower, as was right posterior parietal cortical thickness, while right occipital cortical thickness was greater. Patients in the study were aged 7-17 years. [43]
Morbidity and mortality stem from the metabolic derangements and from the long-term complications that affect small and large vessels, resulting in retinopathy, nephropathy, neuropathy, ischemic heart disease, and arterial obstruction with gangrene of extremities.2 The acute clinical manifestations can be fully understood in the context of current knowledge of the secretion and action of insulin.3 Genetic and other etiologic considerations implicate autoimmune mechanisms in the evolution of the most common form of childhood diabetes, known as type 1a diabetes.4,5 Genetic defects in insulin secretion are increasingly recognized and understood as defining the causes of monogenic forms of diabetes such as maturity-onset diabetes of youth (MODY) and neonatal DM and contributing to the spectrum of T2DM.6
Type 2 diabetes primarily occurs as a result of obesity and lack of exercise.[1] Some people are more genetically at risk than others.[6] Type 2 diabetes makes up about 90% of cases of diabetes, with the other 10% due primarily to diabetes mellitus type 1 and gestational diabetes.[1] In diabetes mellitus type 1 there is a lower total level of insulin to control blood glucose, due to an autoimmune induced loss of insulin-producing beta cells in the pancreas.[12][13] Diagnosis of diabetes is by blood tests such as fasting plasma glucose, oral glucose tolerance test, or glycated hemoglobin (A1C).[3]
Family or personal history. Your risk increases if you have prediabetes — a precursor to type 2 diabetes — or if a close family member, such as a parent or sibling, has type 2 diabetes. You're also at greater risk if you had gestational diabetes during a previous pregnancy, if you delivered a very large baby or if you had an unexplained stillbirth.
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]

WELL-CONTROLLED DIABETES MELLITUS: Daily blood sugar abstracted from the records of a patient whose DM is well controlled (hemoglobin A1c=6.4). The average capillary blood glucose level is 104 mg/dL, and the standard deviation is 19. Sixty-five percent of the readings are between 90 and 140 mg/dL; the lowest blood sugar is 67 mg/dL (on April 15) and the highest is about 190 (on March 21).
One of the most common ways people with type 2 diabetes attempt to lower their blood sugar is by drastically reducing their intake of carbs. The ADA agrees that carbohydrate counting is essential if you have diabetes, but extreme diets like the ketogenic diet, which reduces carb intake to as little as 5 percent of your daily calories, can be risky for some people with diabetes. (36)

The causes of diabetes mellitus are unclear, however, there seem to be both hereditary (genetic factors passed on in families) and environmental factors involved. Research has shown that some people who develop diabetes have common genetic markers. In Type I diabetes, the immune system, the body's defense system against infection, is believed to be triggered by a virus or another microorganism that destroys cells in the pancreas that produce insulin. In Type II diabetes, age, obesity, and family history of diabetes play a role.


"Brittle" diabetes, also known as unstable diabetes or labile diabetes, is a term that was traditionally used to describe the dramatic and recurrent swings in glucose levels, often occurring for no apparent reason in insulin-dependent diabetes. This term, however, has no biologic basis and should not be used.[39] Still, type 1 diabetes can be accompanied by irregular and unpredictable high blood sugar levels, frequently with ketosis, and sometimes with serious low blood sugar levels. Other complications include an impaired counterregulatory response to low blood sugar, infection, gastroparesis (which leads to erratic absorption of dietary carbohydrates), and endocrinopathies (e.g., Addison's disease).[39] These phenomena are believed to occur no more frequently than in 1% to 2% of persons with type 1 diabetes.[40]

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.
Diabetes mellitus (DM) is best defined as a syndrome characterized by inappropriate fasting or postprandial hyperglycemia, caused by absolute or relative insulin deficiency and its metabolic consequences, which include disturbed metabolism of protein and fat. This syndrome results from a combination of deficiency of insulin secretion and its action. Diabetes mellitus occurs when the normal constant of the product of insulin secretion times insulin sensitivity, a parabolic function termed the “disposition index” (Figure 19-1), is inadequate to prevent hyperglycemia and its clinical consequences of polyuria, polydipsia, and weight loss. At high degrees of insulin sensitivity, small declines in the ability to secrete insulin cause only mild, clinically imperceptible defects in glucose metabolism. However, irrespective of insulin sensitivity, a minimum amount of insulin is necessary for normal metabolism. Thus, near absolute deficiency of insulin must result in severe metabolic disturbance as occurs in type 1 diabetes mellitus (T1DM). By contrast, with decreasing sensitivity to its action, higher amounts of insulin secretion are required for a normal disposition index. At a critical point in the disposition index curve (see Figure 19-1), a further small decrement in insulin sensitivity requires a large increase in insulin secretion; those who can mount these higher rates of insulin secretion retain normal glucose metabolism, whereas those who cannot increase their insulin secretion because of genetic or acquired defects now manifest clinical diabetes as occurs in type 2 diabetes (T2DM).
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]
The prognosis for a person with this health condition is estimated to be a life expectancy of 10 years less than a person without diabetes. However, good blood sugar control and taking steps to prevent complications is shortening this gap and people with the condition are living longer than ever before. It can be reversed with diligent attention to changing lifestyle behaviors.
Patients with type 1 DM, unless they have had a pancreatic transplant, require insulin to live; intensive therapy with insulin to limit hyperglycemia (“tight control”) is more effective than conventional therapy in preventing the progression of serious microvascular complications such as kidney and retinal diseases. Intensive therapy consists of three or more doses of insulin injected or administered by infusion pump daily, with frequent self-monitoring of blood glucose levels as well as frequent changes in therapy as a result of contacts with health care professionals. Some negative aspects of intensive therapy include a three times more frequent occurrence of severe hypoglycemia, weight gain, and an adverse effect on serum lipid levels, i.e., a rise in total cholesterol, LDL cholesterol, and triglycerides and a fall in HDL cholesterol. Participation in an intensive therapy program requires a motivated patient, but it can dramatically reduce eye, nerve, and renal complications compared to conventional therapy. See: insulin pump for illus.

Diabetes can be hard enough as it is, so do what you can to make life with it less complicated. For example, you don't have to be a master chef to put together a healthy meal. You can use ingredients that are right in your home. If you find your medication regimen to be too complex or too expensive, request that your physician change it. If you continue to forget to take your medicines, find simple ways to help you take them, like setting a reminder on your cell phone.
In patients with type 2 diabetes, stress, infection, and medications (such as corticosteroids) can also lead to severely elevated blood sugar levels. Accompanied by dehydration, severe blood sugar elevation in patients with type 2 diabetes can lead to an increase in blood osmolality (hyperosmolar state). This condition can worsen and lead to coma (hyperosmolar coma). A hyperosmolar coma usually occurs in elderly patients with type 2 diabetes. Like diabetic ketoacidosis, a hyperosmolar coma is a medical emergency. Immediate treatment with intravenous fluid and insulin is important in reversing the hyperosmolar state. Unlike patients with type 1 diabetes, patients with type 2 diabetes do not generally develop ketoacidosis solely on the basis of their diabetes. Since in general, type 2 diabetes occurs in an older population, concomitant medical conditions are more likely to be present, and these patients may actually be sicker overall. The complication and death rates from hyperosmolar coma is thus higher than in diabetic ketoacidosis.
If you recognize any of the symptoms, contact your doctor immediately. A simple in-office test for sugar in the urine is used for diagnosis. If that test is positive, then a drop of blood from the fingertip will confirm diabetes. Every day, thousands of adults and children around the world are diagnosed, but many go undetected. Early diagnosis cannot prevent Type 1, but it can head off potentially devastating, even fatal, health concerns.
How to use basal insulin: Benefits, types, and dosage Basal, or background, insulin helps regulate blood sugar levels in people diagnosed with diabetes. It keeps glucose levels steady throughout the day and night. It is taken as injections, once a day or more often. The type of insulin and number of daily injections varies. Find out more about the options available. Read now
It isn't always easy to start an exercise regimen, but once you get into a groove, you may be surprised at how much you enjoy it. Find a way to fit activity into your daily routine. Even a few minutes a day goes a long way. The American Diabetes Association recommends that adults with diabetes should perform at least 150 minutes of moderate-intensity aerobic physical activity per week (spread over at least three days with no more than two consecutive days without exercise). You don't have to start with this right away, though. Start with five to 10 minutes per day and go from there. To stay motivated, find a buddy, get a fitness tracker, or use another measurement tool that can help you see your progress.

Hypoglycemia, or low blood sugar, can be caused by too much insulin, too little food (or eating too late to coincide with the action of the insulin), alcohol consumption, or increased exercise. A patient with symptoms of hypoglycemia may be hungry, cranky, confused, and tired. The patient may become sweaty and shaky. Left untreated, the patient can lose consciousness or have a seizure. This condition is sometimes called an insulin reaction and should be treated by giving the patient something sweet to eat or drink like a candy, sugar cubes, juice, or another high sugar snack.
Diet and moderate exercise are the first treatments implemented in diabetes. For many Type II diabetics, weight loss may be an important goal in helping them to control their diabetes. A well-balanced, nutritious diet provides approximately 50-60% of calories from carbohydrates, approximately 10-20% of calories from protein, and less than 30% of calories from fat. The number of calories required by an individual depends on age, weight, and activity level. The calorie intake also needs to be distributed over the course of the entire day so surges of glucose entering the blood system are kept to a minimum.

People with glucose levels between normal and diabetic have impaired glucose tolerance (IGT) or insulin resistance. People with impaired glucose tolerance do not have diabetes, but are at high risk for progressing to diabetes. Each year, 1% to 5% of people whose test results show impaired glucose tolerance actually eventually develop diabetes. Weight loss and exercise may help people with impaired glucose tolerance return their glucose levels to normal. In addition, some physicians advocate the use of medications, such as metformin (Glucophage), to help prevent/delay the onset of overt diabetes.
Doctors and people with diabetes have observed that infections seem more common if you have diabetes. Research in this area, however, has not proved whether this is entirely true, nor why. It may be that high levels of blood sugar impair your body's natural healing process and your ability to fight infections. For women, bladder and vaginal infections are especially common.
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.
×