Brittle diabetics are a subgroup of Type I where patients have frequent and rapid swings of blood sugar levels between hyperglycemia (a condition where there is too much glucose or sugar in the blood) and hypoglycemia (a condition where there are abnormally low levels of glucose or sugar in the blood). These patients may require several injections of different types of insulin during the day to keep the blood sugar level within a fairly normal range.
All types of diabetes mellitus have something in common. Normally, your body breaks down the sugars and carbohydrates you eat into a special sugar called glucose. Glucose fuels the cells in your body. But the cells need insulin, a hormone, in your bloodstream in order to take in the glucose and use it for energy. With diabetes mellitus, either your body doesn't make enough insulin, it can't use the insulin it does produce, or a combination of both.
Insulin is a hormone that is produced by specialized cells (beta cells) of the pancreas. (The pancreas is a deep-seated organ in the abdomen located behind the stomach.) In addition to helping glucose enter the cells, insulin is also important in tightly regulating the level of glucose in the blood. After a meal, the blood glucose level rises. In response to the increased glucose level, the pancreas normally releases more insulin into the bloodstream to help glucose enter the cells and lower blood glucose levels after a meal. When the blood glucose levels are lowered, the insulin release from the pancreas is turned down. It is important to note that even in the fasting state there is a low steady release of insulin than fluctuates a bit and helps to maintain a steady blood sugar level during fasting. In normal individuals, such a regulatory system helps to keep blood glucose levels in a tightly controlled range. As outlined above, in patients with diabetes, the insulin is either absent, relatively insufficient for the body's needs, or not used properly by the body. All of these factors cause elevated levels of blood glucose (hyperglycemia).
A fingerstick glucose test is most often used to monitor blood glucose. Most blood glucose monitoring devices (glucose meters) use a drop of blood obtained by pricking the tip of the finger with a small lancet. The lancet holds a tiny needle that can be jabbed into the finger or placed in a spring-loaded device that easily and quickly pierces the skin. Most people find that the pricking causes only minimal discomfort. Then, a drop of blood is placed on a reagent strip. The strip contains chemicals that undergo changes depending on the glucose level. The glucose meter reads the changes in the test strip and reports the result on a digital display. Some devices allow the blood sample to be obtained from other sites, such as the palm, forearm, upper arm, thigh, or calf. Home glucose meters are smaller than a deck of cards.

A 2009 study shows how genetic information may shed light on the environment-gene interactions that lead to type 1. In the study, researchers found that one of the type 1 genes mediates the immune system's response to viruses. This finding supported the longtime hypothesis that a virus may somehow make the immune system attack the insulin-producing cells in the pancreas in people who are genetically susceptible to developing diabetes.
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.

George P Chrousos, MD, FAAP, MACP, MACE, FRCP(London) is a member of the following medical societies: American Academy of Pediatrics, American College of Physicians, American Pediatric Society, American Society for Clinical Investigation, Association of American Physicians, Endocrine Society, Pediatric Endocrine Society, Society for Pediatric Research, American College of Endocrinology

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.

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.


*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.


Diabetes Mellitus Diabetes Mellitus Complications Diabetes Mellitus Control in Hospital Diabetes Mellitus Glucose Management Diabetes Resources Diabetes Sick Day Management Diabetic Ketoacidosis Diabetic Ketoacidosis Management in Adults Diabetic Ketoacidosis Management in Children Diabetic Ketoacidosis Related Cerebral Edema Hyperosmolar Hyperglycemic State Metabolic Syndrome Type 1 Diabetes Mellitus Type 2 Diabetes Mellitus Type 2 Diabetes Mellitus in Children
Jump up ^ Santaguida PL, Balion C, Hunt D, Morrison K, Gerstein H, Raina P, Booker L, Yazdi H. "Diagnosis, Prognosis, and Treatment of Impaired Glucose Tolerance and Impaired Fasting Glucose". Summary of Evidence Report/Technology Assessment, No. 128. Agency for Healthcare Research and Quality. Archived from the original on 16 September 2008. Retrieved 20 July 2008.

central diabetes insipidus a metabolic disorder due to injury of the neurohypophyseal system, which results in a deficient quantity of antidiuretic hormone (ADH or vasopressin) being released or produced, resulting in failure of tubular reabsorption of water in the kidney. As a consequence, there is the passage of a large amount of urine having a low specific gravity, and great thirst; it is often attended by voracious appetite, loss of strength, and emaciation. Diabetes insipidus may be acquired through infection, neoplasm, trauma, or radiation injuries to the posterior lobe of the pituitary gland or it may be inherited or idiopathic.
Jump up ^ Haw JS, Galaviz KI, Straus AN, Kowalski AJ, Magee MJ, Weber MB, Wei J, Narayan KM, Ali MK (December 2017). "Long-term Sustainability of Diabetes Prevention Approaches: A Systematic Review and Meta-analysis of Randomized Clinical Trials". JAMA Internal Medicine. 177 (12): 1808–1817. doi:10.1001/jamainternmed.2017.6040. PMC 5820728. PMID 29114778.
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.
Other potentially important mechanisms associated with type 2 diabetes and insulin resistance include: increased breakdown of lipids within fat cells, resistance to and lack of incretin, high glucagon levels in the blood, increased retention of salt and water by the kidneys, and inappropriate regulation of metabolism by the central nervous system.[10] However, not all people with insulin resistance develop diabetes, since an impairment of insulin secretion by pancreatic beta cells is also required.[13]
Several other signs and symptoms can mark the onset of diabetes although they are not specific to the disease. In addition to the known ones above, they include blurred vision, headache, fatigue, slow healing of cuts, and itchy skin. Prolonged high blood glucose can cause glucose absorption in the lens of the eye, which leads to changes in its shape, resulting in vision changes. Long-term vision loss can also be caused by diabetic retinopathy. A number of skin rashes that can occur in diabetes are collectively known as diabetic dermadromes.[23]

Diabetes mellitus is a public health problem around the world. In 1980, 108 million adults worldwide had diabetes (4.7% of the global population). By 2014 this had risen to 422 million adults (8.5% of the global population). By 2040, the number is expected to be 642 million adults. In the UK, there is estimated to be between 3 and 4 million people with diabetes. Type 2 diabetes accounts for more than 90% of all patients with diabetes. 


Nerve damage (neuropathy). Excess sugar can injure the walls of the tiny blood vessels (capillaries) that nourish your nerves, especially in the legs. This can cause tingling, numbness, burning or pain that usually begins at the tips of the toes or fingers and gradually spreads upward. Poorly controlled blood sugar can eventually cause you to lose all sense of feeling in the affected limbs. Damage to the nerves that control digestion can cause problems with nausea, vomiting, diarrhea or constipation. For men, erectile dysfunction may be an issue.
Diabetes mellitus (DM), commonly referred to as diabetes, is a group of metabolic disorders in which there are high blood sugar levels over a prolonged period.[10] Symptoms of high blood sugar include frequent urination, increased thirst, and increased hunger.[2] If left untreated, diabetes can cause many complications.[2] Acute complications can include diabetic ketoacidosis, hyperosmolar hyperglycemic state, or death.[3] Serious long-term complications include cardiovascular disease, stroke, chronic kidney disease, foot ulcers, and damage to the eyes.[2]

Diabetes mellitus (DM), commonly referred to as diabetes, is a group of metabolic disorders in which there are high blood sugar levels over a prolonged period.[10] Symptoms of high blood sugar include frequent urination, increased thirst, and increased hunger.[2] If left untreated, diabetes can cause many complications.[2] Acute complications can include diabetic ketoacidosis, hyperosmolar hyperglycemic state, or death.[3] Serious long-term complications include cardiovascular disease, stroke, chronic kidney disease, foot ulcers, and damage to the eyes.[2]
Diabetes is among the leading causes of kidney failure, but its frequency varies between populations and is also related to the severity and duration of the disease. Several measures to slow down the progress of renal damage have been identified. They include control of high blood glucose, control of high blood pressure, intervention with medication in the early stage of kidney damage, and restriction of dietary protein. Screening and early detection of diabetic kidney disease are an important means of prevention.
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.
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.

Metformin is generally recommended as a first line treatment for type 2 diabetes, as there is good evidence that it decreases mortality.[6] It works by decreasing the liver's production of glucose.[87] Several other groups of drugs, mostly given by mouth, may also decrease blood sugar in type II DM. These include agents that increase insulin release, agents that decrease absorption of sugar from the intestines, and agents that make the body more sensitive to insulin.[87] When insulin is used in type 2 diabetes, a long-acting formulation is usually added initially, while continuing oral medications.[6] Doses of insulin are then increased to effect.[6][88]


Progression toward type 2 diabetes may even be self-perpetuating. Once a person begins to become insulin resistant, for whatever reason, things may snowball from there. The increased levels of circulating insulin required to compensate for resistance encourage the body to pack on pounds. That extra weight will in turn make the body more insulin resistant. Furthermore, the heavier a person is, the more difficult it can be to exercise, continuing the slide toward diabetes.
Sources of processed or added sugar, including condiments, honey, and especially sugary drinks, are just a few of the potential culprits for weight gain, Grieger says, and it’s when they’re consumed in excess that they can contribute to diabetes risk. “The largest source of added sugar comes from sweetened beverages. They run the gamut of soda, sweetened tea, juices with added sugar, sports drinks — it’s a plethora. Just about everything we drink has added sugar in it, except for water,” she explains.
Other potentially important mechanisms associated with type 2 diabetes and insulin resistance include: increased breakdown of lipids within fat cells, resistance to and lack of incretin, high glucagon levels in the blood, increased retention of salt and water by the kidneys, and inappropriate regulation of metabolism by the central nervous system.[10] However, not all people with insulin resistance develop diabetes, since an impairment of insulin secretion by pancreatic beta cells is also required.[13]
People with type 1 diabetes and certain people with type 2 diabetes may use carbohydrate counting or the carbohydrate exchange system to match their insulin dose to the carbohydrate content of their meal. "Counting" the amount of carbohydrate in a meal is used to calculate the amount of insulin the person takes before eating. However, the carbohydrate-to-insulin ratio (the amount of insulin taken for each gram of carbohydrate in the meal) varies for each person, and people with diabetes need to work closely with a dietician who has experience in working with people with diabetes to master the technique. Some experts have advised use of the glycemic index (a measure of the impact of an ingested carbohydrate-containing food on the blood glucose level) to delineate between rapid and slowly metabolized carbohydrates, although there is little evidence to support this approach.

The term "type 1 diabetes" has replaced several former terms, including childhood-onset diabetes, juvenile diabetes, and insulin-dependent diabetes mellitus (IDDM). Likewise, the term "type 2 diabetes" has replaced several former terms, including adult-onset diabetes, obesity-related diabetes, and noninsulin-dependent diabetes mellitus (NIDDM). Beyond these two types, there is no agreed-upon standard nomenclature.[citation needed]
How is it treated? There is no uniform therapy for type 2 diabetes treatment, which depends on the individual person and his or her stage of type 2 diabetes. To learn more about individualization of therapy, please read our patient guide. That said, the ADA and EASD have created treatment recommendation guidelines for type 2 diabetes progression. In all cases, healthy eating, exercise, and weight management are key to effective type 2 diabetes management. As type 2 diabetes progresses, patients may need to add one or more drugs to their treatment regimen.

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.
Some people who have type 2 diabetes can achieve their target blood sugar levels with diet and exercise alone, but many also need diabetes medications or insulin therapy. The decision about which medications are best depends on many factors, including your blood sugar level and any other health problems you have. Your doctor might even combine drugs from different classes to help you control your blood sugar in several different ways.
These diabetes complications are related to blood vessel diseases and are generally classified into small vessel disease, such as those involving the eyes, kidneys and nerves (microvascular disease), and large vessel disease involving the heart and blood vessels (macrovascular disease). Diabetes accelerates hardening of the arteries (atherosclerosis) of the larger blood vessels, leading to coronary heart disease (angina or heart attack), strokes, and pain in the lower extremities because of lack of blood supply (claudication).

Hemoglobin A1c or HbA1c is a protein on the surface of red blood cells. The HbA1c test is used to monitor blood sugar levels in people with type 1 and type 2 diabetes over time. Normal HbA1c levels are 6% or less. HbA1c levels can be affected by insulin use, fasting, glucose intake (oral or IV), or a combination of these and other factors. High hemoglobin A1c levels in the blood increases the risk of microvascular complications, for example, diabetic neuropathy, eye, and kidney disease.

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