"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.
Hyperglycemia or high blood sugar is a serious health problem for diabetics. There are two types of hyperglycemia, 1) fasting, and 2)postprandial or after meal hyperglycemia. Hyperglycemia can also lead to ketoacidosis or hyperglycemic hyperosmolar nonketotic syndrome (HHNS). There are a variety of causes of hyperglycemia in people with diabetes. Symptoms of high blood sugar may include increased thirst, headaches, blurred vision, and frequent urination.Treatment can be achieved through lifestyle changes or medications changes. Carefully monitoring blood glucose levels is key to prevention.
Insulin is vital to patients with type 1 diabetes - they cannot live without a source of exogenous insulin. Without insulin, patients with type 1 diabetes develop severely elevated blood sugar levels. This leads to increased urine glucose, which in turn leads to excessive loss of fluid and electrolytes in the urine. Lack of insulin also causes the inability to store fat and protein along with breakdown of existing fat and protein stores. This dysregulation, results in the process of ketosis and the release of ketones into the blood. Ketones turn the blood acidic, a condition called diabetic ketoacidosis (DKA). Symptoms of diabetic ketoacidosis include nausea, vomiting, and abdominal pain. Without prompt medical treatment, patients with diabetic ketoacidosis can rapidly go into shock, coma, and even death may result.
Another area of pathologic changes associated with diabetes mellitus is the nervous system (diabetic neuropathy), particularly in the peripheral nerves of the lower extremities. The patient typically experiences a “stocking-type” anesthesia beginning about 10 years after the onset of the disease. There may eventually be almost total anesthesia of the affected part with the potential for serious injury to the part without the patient being aware of it. In contrast, some patients experience debilitating pain and hyperesthesia, with loss of deep tendon reflexes.
No major organization recommends universal screening for diabetes as there is no evidence that such a program improve outcomes.[54][55] Screening is recommended by the United States Preventive Services Task Force (USPSTF) in adults without symptoms whose blood pressure is greater than 135/80 mmHg.[56] For those whose blood pressure is less, the evidence is insufficient to recommend for or against screening.[56] There is no evidence that it changes the risk of death in this group of people.[55] They also recommend screening among those who are overweight and between the ages of 40 and 70.[57]
Type 2 diabetes is typically a chronic disease associated with a ten-year-shorter life expectancy.[10] This is partly due to a number of complications with which it is associated, including: two to four times the risk of cardiovascular disease, including ischemic heart disease and stroke; a 20-fold increase in lower limb amputations, and increased rates of hospitalizations.[10] In the developed world, and increasingly elsewhere, type 2 diabetes is the largest cause of nontraumatic blindness and kidney failure.[24] It has also been associated with an increased risk of cognitive dysfunction and dementia through disease processes such as Alzheimer's disease and vascular dementia.[25] Other complications include acanthosis nigricans, sexual dysfunction, and frequent infections.[23]
Weight loss surgery in those who are obese is an effective measure to treat diabetes.[101] Many are able to maintain normal blood sugar levels with little or no medication following surgery[102] and long-term mortality is decreased.[103] There however is some short-term mortality risk of less than 1% from the surgery.[104] The body mass index cutoffs for when surgery is appropriate are not yet clear.[103] It is recommended that this option be considered in those who are unable to get both their weight and blood sugar under control.[105][106]
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.
Accelerated atherosclerosis is the main underlying factor contributing to the high risk of atherothrombotic events in DM patients. CAD, peripheral vascular disease, stroke, and increased intima-media thickness are the main macrovascular complications. Diabetics are 2–4 times more likely to develop stroke than people without DM.2 CVD, particularly CAD, is the leading cause of morbidity and mortality in patients with DM.4 Patients with T2DM have a 2- to 4-fold increase in the risk of CAD, and patients with DM but without previous myocardial infarction (MI) carry the same level of risk for subsequent acute coronary events as nondiabetic patients with previous MI.5 Furthermore, people with diabetes have a poorer long-term prognosis after MI, including an increased risk for congestive heart failure and death.
But the 2015-2020 Dietary Guidelines recommend keeping added sugar below 10 percent of your overall daily caloric intake. And the American Heart Association suggests consuming no more than 9 teaspoons (tsp) — equal to 36 grams (g) or 150 calories — of added sugar if you're a man, and 6 tsp — equal to 25 g or 100 calories — if you're a woman. "Naturally occurring sugars don't count in these recommendations," notes Grieger, which means you should worry less about those sugars in fruits and veggies, for instance, than you should about those in processed fare.
Treatment of high blood pressure and high cholesterol levels, which can contribute to circulation problems, can help prevent some of the complications of diabetes as well. A low dose of aspirin taken daily is recommended in people with risk factors for heart disease. All people with diabetes who are between 40 and 75 years are given a statin (a drug to decrease cholesterol levels) regardless of cholesterol levels. Younger people with an elevated risk of heart disease should also take a statin .

Beta cells are vulnerable to more than just bad genes, which may explain the associations between type 2 diabetes and environmental factors that aren't related to how much fat a body has or where it is stored. Beta cells carry vitamin D receptors on their surface, and people with vitamin D deficiency are at increased risk for type 2. Plus, several studies have shown that people with higher levels of toxic substances in their blood—such as from the PCBs found in fish fat—are at increased risk of type 2 diabetes, though a cause-and-effect relationship hasn't been proved. (Toxic substances and vitamin D have also been implicated in type 1 diabetes, but the disease mechanism may be unrelated to what's going on in type 2.)
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.

Jump up ^ Boussageon, R; Bejan-Angoulvant, T; Saadatian-Elahi, M; Lafont, S; Bergeonneau, C; Kassaï, B; Erpeldinger, S; Wright, JM; Gueyffier, F; Cornu, C (2011-07-26). "Effect of intensive glucose lowering treatment on all cause mortality, cardiovascular death, and microvascular events in type 2 diabetes: meta-analysis of randomised controlled trials". The BMJ. 343: d4169. doi:10.1136/bmj.d4169. PMC 3144314. PMID 21791495.


Rates of type 2 diabetes have increased markedly since 1960 in parallel with obesity.[17] As of 2015 there were approximately 392 million people diagnosed with the disease compared to around 30 million in 1985.[11][18] Typically it begins in middle or older age,[6] although rates of type 2 diabetes are increasing in young people.[19][20] Type 2 diabetes is associated with a ten-year-shorter life expectancy.[10] Diabetes was one of the first diseases described.[21] The importance of insulin in the disease was determined in the 1920s.[22]
The American Diabetes Association sponsored an international panel in 1995 to review the literature and recommend updates of the classification of diabetes mellitus. The definitions and descriptions that follow are drawn from the Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. The report was first approved in 1997 and modified in 1999. Although other terms are found in older literature and remain in use, their use in current clinical practice is inappropriate. Epidemiologic and research studies are facilitated by use of a common language.

Doctors may recommend one or more types of medications to help control diabetes. While taking medications, it's important for people with diabetes to regularly test their blood glucose levels at home. There are many different blood glucose meters available on the market. Speak to a doctor or pharmacist about these meters to help you select the best meter for your needs.
Diabetes mellitus is a chronic disease, for which there is no known cure except in very specific situations.[75] Management concentrates on keeping blood sugar levels as close to normal, without causing low blood sugar. This can usually be accomplished with a healthy diet, exercise, weight loss, and use of appropriate medications (insulin in the case of type 1 diabetes; oral medications, as well as possibly insulin, in type 2 diabetes).[medical citation needed]
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).
Diabetes can also result from other hormonal disturbances, such as excessive growth hormone production (acromegaly) and Cushing's syndrome. In acromegaly, a pituitary gland tumor at the base of the brain causes excessive production of growth hormone, leading to hyperglycemia. In Cushing's syndrome, the adrenal glands produce an excess of cortisol, which promotes blood sugar elevation.
The classic symptoms of diabetes are polyuria (frequent urination), polydipsia (increased thirst), polyphagia (increased hunger), and weight loss.[23] Other symptoms that are commonly present at diagnosis include a history of blurred vision, itchiness, peripheral neuropathy, recurrent vaginal infections, and fatigue.[13] Many people, however, have no symptoms during the first few years and are diagnosed on routine testing.[13] A small number of people with type 2 diabetes mellitus can develop a hyperosmolar hyperglycemic state (a condition of very high blood sugar associated with a decreased level of consciousness and low blood pressure).[13]
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.
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.
Although there are dozens of known type 1 genes, about half of the risk attributable to heredity comes from a handful that coordinate a part of the immune system called HLA, which helps the body recognize nefarious foreign invaders, such as viruses, bacteria, and parasites. Type 1 diabetes is an autoimmune disease, in which the body's own immune system destroys the cells in the pancreas that produce insulin, so perhaps it is no surprise that immunity genes are involved. Other autoimmune diseases share the HLA gene link, which may be why people with type 1 are more likely to develop additional auto­immune disorders.
Education: People with diabetes should learn as much as possible about this condition and how to manage it. The more you know about your condition, the better prepared you are to manage it on a daily basis. Many hospitals offer diabetes education programs and many nurses and pharmacists have been certified to provide diabetes education. Contact a local hospital, doctor, or pharmacist to find out about programs and diabetes educators in your area.
Aspirin should be used as secondary prophylaxis in all diabetic people with evidence of macrovascular disease, and it should be strongly considered as primary prevention in diabetic subjects with other risk factors for macrovascular disease, such as hypertension, cigarette smoking, dyslipidemia, obesity, and albuminuria (macro or micro).228 Because of the platelet defects associated with diabetes, it is recommended that the dose of aspirin should be 300 mg per day,228–230 although the American Diabetes Association’s position statement (http://www.diabetes.org/DiabetesCare/supplement198/s45.htm) advocates a dose of 81 to 325 mg enteric-coated aspirin per day. If the patient cannot tolerate aspirin, then clopidogrel231 can be used.
Glucose is a simple sugar found in food. Glucose is an essential nutrient that provides energy for the proper functioning of the body cells. Carbohydrates are broken down in the small intestine and the glucose in digested food is then absorbed by the intestinal cells into the bloodstream, and is carried by the bloodstream to all the cells in the body where it is utilized. However, glucose cannot enter the cells alone and needs insulin to aid in its transport into the cells. Without insulin, the cells become starved of glucose energy despite the presence of abundant glucose in the bloodstream. In certain types of diabetes, the cells' inability to utilize glucose gives rise to the ironic situation of "starvation in the midst of plenty". The abundant, unutilized glucose is wastefully excreted in the urine.
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.

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.

There is evidence that certain emotions can promote type 2 diabetes. A recent study found that depression seems to predispose people to diabetes. Other research has tied emotional stress to diabetes, though the link hasn't been proved. Researchers speculate that the emotional connection may have to do with the hormone cortisol, which floods the body during periods of stress. Cortisol sends glucose to the blood, where it can fuel a fight-or-flight response, but overuse of this system may lead to dysfunction.
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.

Good metabolic control can delay the onset and progression of diabetic retinopathy. Loss of vision and blindness in persons with diabetes can be prevented by early detection and treatment of vision-threatening retinopathy: regular eye examinations and timely intervention with laser treatment, or through surgery in cases of advanced retinopathy. There is evidence that, even in developed countries, a large proportion of those in need is not receiving such care due to lack of public and professional awareness, as well as an absence of treatment facilities. In developing countries, in many of which diabetes is now common, such care is inaccessible to the majority of the population.


When it comes to diabetes, there's no real answer yet. Yes, science has begun to uncover the roots of this disease, unearthing a complex interplay of genes and environment—and a lot more unanswered questions. Meanwhile, there's plenty of misinformation to go around. (How often have you had to explain that diabetes doesn't happen because someone "ate too much"?)
Given the diverse peculiarities involving the issue, studies have shown that Diabetes mellitus has been extensively investigated in its pathophysiological aspects, highlighting the search for strong evidence that can be used in the clinical practice of the Primary Care nurse, with attributions focused on health promotion, prevention of complications, treatment and rehabilitation of the health of individuals and community, carried out in an interdisciplinary and multidisciplinary manner (Matumoto, Fortuna, Kawata, Mishima, & Pereira, 2011; Florianopolis, 2015).
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.
Diabetes develops when the body can't make any or enough insulin, and/or when it can't properly use the insulin it makes. For some people with diabetes, the body becomes resistant to insulin. In these cases, insulin is still produced, but the body does not respond to the effects of insulin as it should. This is called insulin resistance. Whether from not enough insulin or the inability to use insulin properly, the result is high levels of glucose in the blood, or hyperglycemia.

To understand why insulin is important, it helps to know more about how the body uses food for energy. Your body is made up of millions of cells. To make energy, these cells need food in a very simple form. When you eat or drink, much of the food is broken down into a simple sugar called "glucose." Then, glucose is transported through the bloodstream to these cells where it can be used to provide the energy the body needs for daily activities.


Good metabolic control can delay the onset and progression of diabetic retinopathy. Loss of vision and blindness in persons with diabetes can be prevented by early detection and treatment of vision-threatening retinopathy: regular eye examinations and timely intervention with laser treatment, or through surgery in cases of advanced retinopathy. There is evidence that, even in developed countries, a large proportion of those in need is not receiving such care due to lack of public and professional awareness, as well as an absence of treatment facilities. In developing countries, in many of which diabetes is now common, such care is inaccessible to the majority of the population.
The ketogenic, or keto, diet calls for dramatically increasing your fat intake and consuming a moderate amount of protein and a very low amount of carbs, with the aim of kicking your body into a natural metabolic state called ketosis, in which it relies on burning fat rather than carbs for energy. Ketosis is different from diabetic ketoacidosis, a health emergency that occurs when insulin levels are low in conjunction with high levels of ketones. (37) Ketones are by-products of metabolism that are released in the blood when carb intake is low.
Jump up ^ Rubino, F; Nathan, DM; Eckel, RH; Schauer, PR; Alberti, KG; Zimmet, PZ; Del Prato, S; Ji, L; Sadikot, SM; Herman, WH; Amiel, SA; Kaplan, LM; Taroncher-Oldenburg, G; Cummings, DE; Delegates of the 2nd Diabetes Surgery, Summit (June 2016). "Metabolic Surgery in the Treatment Algorithm for Type 2 Diabetes: A Joint Statement by International Diabetes Organizations". Diabetes Care. 39 (6): 861–77. doi:10.2337/dc16-0236. PMID 27222544.
It's not as clear what the rest of the type 1 genes are up to, but researchers are eager to find out. "Even though something accounts for a small part [of the genetic risk], it could have a significant impact," says Stephen Rich, PhD, director of the Center for Public Health Genomics at the University of Virginia School of Medicine. Understanding these genes' role may clue researchers in to less obvious biological pathways involved in type 1 diabetes, and to possible prevention strategies.
Prediabetes is a condition in which blood glucose levels are higher than normal, but a person does not yet have diabetes. Prediabetes and high blood glucose levels are a risk factor for developing diabetes, heart disease, and other health problems. Other warning signs prediabetes may include increased urination, feeling you need to urinate more often, and/or increased thirst.
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