Clear evidence suggests a genetic component in type 1 diabetes mellitus. Monozygotic twins have a 60% lifetime concordance for developing type 1 diabetes mellitus, although only 30% do so within 10 years after the first twin is diagnosed. In contrast, dizygotic twins have only an 8% risk of concordance, which is similar to the risk among other siblings.

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.
Assemble a Medical Team: Whether you've had diabetes for a long time or you've just been diagnosed, there are certain doctors that are important to see. It is extremely important to have a good primary care physician. This type of doctor will help coordinate appointments for other physicians if they think that you need it. Some primary physicians treat diabetes themselves, whereas others will recommend that you visit an endocrinologist for diabetes treatment. An endocrinologist is a person who specializes in diseases of the endocrine system, diabetes being one of them.
Type 2 diabetes is a progressive, chronic disease related to your body's challenges with regulating blood sugar. It is often associated with generalized inflammation. Your pancreas produces the hormone insulin to convert sugar (glucose) to energy that you either use immediately or store. With type 2 diabetes, you are unable to use that insulin efficiently. Although your body produces the hormone, either there isn't enough of it to keep up with the amount of glucose in your system, or the insulin being produced isn't being used as well as it should be, both of which result in high blood sugar levels.
Hyperglycemia (ie, random blood glucose concentration of more than 200 mg/dL or 11 mmol/L) results when insulin deficiency leads to uninhibited gluconeogenesis and prevents the use and storage of circulating glucose. The kidneys cannot reabsorb the excess glucose load, causing glycosuria, osmotic diuresis, thirst, and dehydration. Increased fat and protein breakdown leads to ketone production and weight loss. Without insulin, a child with type 1 diabetes mellitus wastes away and eventually dies due to DKA. The effects of insulin deficiency are shown in the image below.
There are two major types of diabetes, called type 1 and type 2. Type 1 diabetes was also formerly called insulin dependent diabetes mellitus (IDDM), or juvenile-onset diabetes mellitus. In type 1 diabetes, the pancreas undergoes an autoimmune attack by the body itself, and is rendered incapable of making insulin. Abnormal antibodies have been found in the majority of patients with type 1 diabetes. Antibodies are proteins in the blood that are part of the body's immune system. The patient with type 1 diabetes must rely on insulin medication for survival.

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.)
Injections of insulin may either be added to oral medication or used alone.[24] Most people do not initially need insulin.[13] When it is used, a long-acting formulation is typically added at night, with oral medications being continued.[23][24] Doses are then increased to effect (blood sugar levels being well controlled).[24] When nightly insulin is insufficient, twice daily insulin may achieve better control.[23] The long acting insulins glargine and detemir are equally safe and effective,[98] and do not appear much better than neutral protamine Hagedorn (NPH) insulin, but as they are significantly more expensive, they are not cost effective as of 2010.[99] In those who are pregnant insulin is generally the treatment of choice.[23]
Prevention and treatment involve maintaining a healthy diet, regular physical exercise, a normal body weight, and avoiding use of tobacco.[2] Control of blood pressure and maintaining proper foot care are important for people with the disease.[2] Type 1 DM must be managed with insulin injections.[2] Type 2 DM may be treated with medications with or without insulin.[9] Insulin and some oral medications can cause low blood sugar.[13] Weight loss surgery in those with obesity is sometimes an effective measure in those with type 2 DM.[14] Gestational diabetes usually resolves after the birth of the baby.[15]
In type 1 diabetes (formerly called insulin-dependent diabetes or juvenile-onset diabetes), the body's immune system attacks the insulin-producing cells of the pancreas, and more than 90% of them are permanently destroyed. The pancreas, therefore, produces little or no insulin. Only about 5 to 10% of all people with diabetes have type 1 disease. Most people who have type 1 diabetes develop the disease before age 30, although it can develop later in life.
People with type 1 diabetes sometimes receive transplantation of an entire pancreas or of only the insulin-producing cells from a donor pancreas. This procedure may allow people with type 1 diabetes mellitus to maintain normal glucose levels. However, because immunosuppressant drugs must be given to prevent the body from rejecting the transplanted cells, pancreas transplantation is usually done only in people who have serious complications due to diabetes or who are receiving another transplanted organ (such as a kidney) and will require immunosuppressant drugs anyway.
As of 2016, 422 million people have diabetes worldwide,[101] up from an estimated 382 million people in 2013[17] and from 108 million in 1980.[101] Accounting for the shifting age structure of the global population, the prevalence of diabetes is 8.5% among adults, nearly double the rate of 4.7% in 1980.[101] Type 2 makes up about 90% of the cases.[16][18] Some data indicate rates are roughly equal in women and men,[18] but male excess in diabetes has been found in many populations with higher type 2 incidence, possibly due to sex-related differences in insulin sensitivity, consequences of obesity and regional body fat deposition, and other contributing factors such as high blood pressure, tobacco smoking, and alcohol intake.[102][103]
In addition to learning about diabetes itself, older people may have to learn how to fit management of diabetes in with their management of other disorders. Learning about how to avoid complications, such as dehydration, skin breakdown, and circulation problems, and to manage factors that can contribute to complications of diabetes, such as high blood pressure and high cholesterol levels, is especially important. Such problems become more common as people age, whether they have diabetes or not.
A1C: Your A1C, also called glycated hemoglobin, reflects your average blood glucose levels for the past 2 to 3 months. If your A1C is 6.5% or greater, your doctor may diagnose diabetes. If your A1C is between 6.0% and 6.4%, your doctor may diagnose prediabetes. Of note, A1C cannot be used to diagnose type 1 diabetes, diabetes in children, adolescents, or pregnant women.
*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For information on a given medication, check our Drug Information database. For more information on brand names, speak with your doctor or pharmacist.
Diabetic retinopathy is a leading cause of blindness and visual disability. Diabetes mellitus is associated with damage to the small blood vessels in the retina, resulting in loss of vision. Findings, consistent from study to study, make it possible to suggest that, after 15 years of diabetes, approximately 2% of people become blind, while about 10% develop severe visual handicap. Loss of vision due to certain types of glaucoma and cataract may also be more common in people with diabetes than in those without the disease.
Although urine can also be tested for the presence of glucose, checking urine is not a good way to monitor treatment or adjust therapy. Urine testing can be misleading because the amount of glucose in the urine may not reflect the current level of glucose in the blood. Blood glucose levels can get very low or reasonably high without any change in the glucose levels in the urine.
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.
Several common medications can impair the body's use of insulin, causing a condition known as secondary diabetes. These medications include treatments for high blood pressure (furosemide, clonidine, and thiazide diuretics), drugs with hormonal activity (oral contraceptives, thyroid hormone, progestins, and glucocorticorids), and the anti-inflammation drug indomethacin. Several drugs that are used to treat mood disorders (such as anxiety and depression) also can impair glucose absorption. These drugs include haloperidol, lithium carbonate, phenothiazines, tricyclic antidepressants, and adrenergic agonists. Other medications that can cause diabetes symptoms include isoniazid, nicotinic acid, cimetidine, and heparin. A 2004 study found that low levels of the essential mineral chromium in the body may be linked to increased risk for diseases associated with insulin resistance.
Insulin is the hormone responsible for reducing blood sugar. In order for insulin to work, our tissues have to be sensitive to its action; otherwise, tissues become resistant and insulin struggles to clear out sugar from the blood. As insulin resistance sets in, the first organ to stop responding to insulin is the liver, followed by the muscles and eventually fat. How does insulin resistance begin? The root of the problem is our diet.
; DM multiaetiology metabolic disease due to reduced/absent production of pancreatic insulin, and/or insulin resistance by peripheral tissue insulin receptors; characterized by reduced carbohydrate metabolism and increased fat and protein metabolism, leading to hyperglycaemia, increasing glycosuria, water and electrolyte imbalance, ketoacidosis, coma and death if left untreated; chronic long-term complications of DM include nephropathy, retinopathy, neuropathy and generalized degenerative changes in large and small arteries; treatment (with insulin/oral hypoglycaemic agents/diet) aims to stabilize blood glucose levels to the normal range (difficult to achieve fully; patients may tend to hyperglycaemia or hypoglycaemia due to mismanagement of glycaemic control); Tables D4-D7
The development of type 2 diabetes is caused by a combination of lifestyle and genetic factors.[24][26] While some of these factors are under personal control, such as diet and obesity, other factors are not, such as increasing age, female gender, and genetics.[10] A lack of sleep has been linked to type 2 diabetes.[27] This is believed to act through its effect on metabolism.[27] The nutritional status of a mother during fetal development may also play a role, with one proposed mechanism being that of DNA methylation.[28] The intestinal bacteria Prevotella copri and Bacteroides vulgatus have been connected with type 2 diabetes.[29]
Type 2 diabetes used to be called adult-onset diabetes or non-insulin dependent diabetes because it was diagnosed mainly in adults who did not require insulin to manage their condition. However, because more children are starting to be diagnosed with T2D, and insulin is used more frequently to help manage type 2 diabetes, referring to the condition as “adult-onset” or “non-insulin dependent” is no longer accurate.
A population-based, nationwide cohort study in Finland examined the short -and long-term time trends in mortality among patients with early-onset and late-onset type 1 diabetes. The results suggest that in those with early-onset type 1 diabetes (age 0-14 y), survival has improved over time. Survival of those with late-onset type 1 diabetes (15-29 y) has deteriorated since the 1980s, and the ratio of deaths caused by acute complications has increased in this group. Overall, alcohol was noted as an important cause of death in patients with type 1 diabetes; women had higher standardized mortality ratios than did men in both groups. [38]
Medications used to treat diabetes do so by lowering blood sugar levels. There is broad consensus that when people with diabetes maintain tight glucose control (also called "tight glycemic control") -- keeping the glucose levels in their blood within normal ranges - that they experience fewer complications like kidney problems and eye problems.[84][85] There is however debate as to whether this is cost effective for people later in life.[86]

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 is 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.
Diabetes: The differences between types 1 and 2 There are fundamental differences between diabetes type 1 and type 2, including when they might occur, their causes, and how they affect someone's life. Find out here what distinguishes the different forms of the disease, the various symptoms, treatment methods, and how blood tests are interpreted. Read now
If you have type 2 diabetes and your body mass index (BMI) is greater than 35, you may be a candidate for weight-loss surgery (bariatric surgery). Blood sugar levels return to normal in 55 to 95 percent of people with diabetes, depending on the procedure performed. Surgeries that bypass a portion of the small intestine have more of an effect on blood sugar levels than do other weight-loss surgeries.
Per the WHO, people with fasting glucose levels from 6.1 to 6.9 mmol/l (110 to 125 mg/dl) are considered to have impaired fasting glucose.[67] people with plasma glucose at or above 7.8 mmol/l (140 mg/dl), but not over 11.1 mmol/l (200 mg/dl), two hours after a 75 gram oral glucose load are considered to have impaired glucose tolerance. Of these two prediabetic states, the latter in particular is a major risk factor for progression to full-blown diabetes mellitus, as well as cardiovascular disease.[68] The American Diabetes Association (ADA) since 2003 uses a slightly different range for impaired fasting glucose of 5.6 to 6.9 mmol/l (100 to 125 mg/dl).[69]

Weight fluctuations also fall under the umbrella of possible diabetes signs and symptoms. When you lose sugar through frequent urination, you also lose calories. At the same time, diabetes may keep the sugar from your food from reaching your cells — leading to constant hunger. The combined effect is potentially rapid weight loss, especially if you have type 1 diabetes.
The pain of diabetic nerve damage may respond to traditional treatments with certain medications such as gabapentin (Neurontin), phenytoin (Dilantin), and carbamazepine (Tegretol) that are traditionally used in the treatment of seizure disorders. Amitriptyline (Elavil, Endep) and desipramine (Norpraminine) are medications that are traditionally used for depression. While many of these medications are not indicated specifically for the treatment of diabetes related nerve pain, they are used by physicians commonly.

In ‘type 2 diabetes’ (previously called non-insulin-dependent diabetes mellitus), which accounts for 90% of all diabetes, the beta cells do not stop making insulin completely, but the insulin produced does not work properly so it struggles to store the sugar found in the blood. As a consequence, the pancreas has to produce more insulin to compensate for this reduction in insulin function. This is called insulin resistance and is commonly linked to obesity. This type of diabetes is seen more commonly over the age of 40 years but can occur at any age.  


People with type 1 diabetes sometimes receive transplantation of an entire pancreas or of only the insulin-producing cells from a donor pancreas. This procedure may allow people with type 1 diabetes mellitus to maintain normal glucose levels. However, because immunosuppressant drugs must be given to prevent the body from rejecting the transplanted cells, pancreas transplantation is usually done only in people who have serious complications due to diabetes or who are receiving another transplanted organ (such as a kidney) and will require immunosuppressant drugs anyway.


Type 1 diabetes occurs when your immune system, the body’s system for fighting infection, attacks and destroys the insulin-producing beta cells of the pancreas. Scientists think type 1 diabetes is caused by genes and environmental factors, such as viruses, that might trigger the disease. Studies such as TrialNet are working to pinpoint causes of type 1 diabetes and possible ways to prevent or slow the disease.
The term "diabetes" or "to pass through" was first used in 230 BCE by the Greek Apollonius of Memphis.[108] The disease was considered rare during the time of the Roman empire, with Galen commenting he had only seen two cases during his career.[108] This is possibly due to the diet and lifestyle of the ancients, or because the clinical symptoms were observed during the advanced stage of the disease. Galen named the disease "diarrhea of the urine" (diarrhea urinosa).[110]
Diabetes mellitus is linked with an increased risk of heart attacks, strokes, poor blood circulation to the legs and damage to the eyes, feet and kidneys. Early diagnosis and strict control of blood sugar, blood pressure and cholesterol levels can help to prevent or delay these complications associated with diabetes. Maintaining a healthy lifestyle (regular exercise, eating healthily and maintaining a healthy weight) is important in reducing the risk of developing type 2 diabetes.

There are a range of different symptoms in people with diabetes. They may feel thirsty, pass a large amount of urine, wake up overnight to pass urine, lose weight and have blurred vision. Patients are vulnerable to infections such as thrush and may present with this. Particularly in type 2 diabetes, patients may not be aware of their diabetes for several years and a diagnosis may only be made when they seek treatment for diabetes-related complications such as foot, eye or kidney problems. Some patients may become severely ill and be taken into hospital with an infection and/or very high blood sugar levels.


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.
Several common medications can impair the body's use of insulin, causing a condition known as secondary diabetes. These medications include treatments for high blood pressure (furosemide, clonidine, and thiazide diuretics), drugs with hormonal activity (oral contraceptives, thyroid hormone, progestins, and glucocorticorids), and the anti-inflammation drug indomethacin. Several drugs that are used to treat mood disorders (such as anxiety and depression) also can impair glucose absorption. These drugs include haloperidol, lithium carbonate, phenothiazines, tricyclic antidepressants, and adrenergic agonists. Other medications that can cause diabetes symptoms include isoniazid, nicotinic acid, cimetidine, and heparin. A 2004 study found that low levels of the essential mineral chromium in the body may be linked to increased risk for diseases associated with insulin resistance.
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.
 Type 1 diabetes mellitus is a chronic metabolic syndrome defined by an inability to produce insulin, a hormone which lowers blood sugar. This leads to inappropriate hyperglycaemia (increased blood sugar levels) and deranged metabolism of carbohydrates, fats and proteins. Insulin is normally produced in the pancreas, a glandular organ involved in the production of digestive enzymes and hormones such as insulin and glucagon. These functions are carried out in the exocrine and endocrine (Islets of Langerhans) pancreas respectively.

Type 1 Diabetes: About 5 to 10 percent of those with diabetes have type 1 diabetes. It's an autoimmune disease, meaning the body's own immune system mistakenly attacks and destroys the insulin-producing cells in the pancreas. Patients with type 1 diabetes have very little or no insulin, and must take insulin everyday. Although the condition can appear at any age, typically it's diagnosed in children and young adults, which is why it was previously called juvenile diabetes.
Over recent decades, and particularly in the past five years, researchers have found dozens of genes with links to diabetes. The count stands at about 50 genes for type 1 and 38 for type 2. The numbers have risen quickly in recent years because of advances in the gene-sequencing technology used to conduct genome-wide association studies. This technique involves taking the genetic compositions of a group of people with a disease and comparing them en masse to the genomes of people who don't have the disease.
Diabetes means your blood glucose, or blood sugar, levels are too high. With type 2 diabetes, the more common type, your body does not make or use insulin well. Insulin is a hormone that helps glucose get into your cells to give them energy. Without insulin, too much glucose stays in your blood. Over time, high blood glucose can lead to serious problems with your heart, eyes, kidneys, nerves, and gums and teeth.
gestational diabetes diabetes mellitus with onset or first recognition during pregnancy, usually during the second or third trimester. In some cases mild, undetected glucose intolerance was present before pregnancy. It often disappears after the end of the pregnancy, but many women with this condition develop permanent diabetes mellitus in later life. Although the disordered carbohydrate metabolism is usually mild, prompt detection and treatment are necessary to avoid fetal and neonatal morbidity and mortality.
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.
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