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)

In the United States alone, more than 8 million people have undiagnosed diabetes, according to the American Diabetes Association. But you don't need to become a statistic. Understanding possible diabetes symptoms can lead to early diagnosis and treatment — and a lifetime of better health. If you're experiencing any of the following diabetes signs and symptoms, see your doctor.
Persons with diabetes are prone to infection, delayed healing, and vascular disease. The ease with which poorly controlled diabetic persons develop an infection is thought to be due in part to decreased chemotaxis of leukocytes, abnormal phagocyte function, and diminished blood supply because of atherosclerotic changes in the blood vessels. An impaired blood supply means a deficit in the protective defensive cells transported in the blood. Excessive glucose allows organisms to grow out of control.
While many experts believe that most type 1 genes have been identified, the situation with type 2 diabetes is much different. A recent study found that the known genetic links to type 2 probably account for only about 6 percent of the genetic predisposition for that form of diabetes. This could mean either that some of the genes discovered have a bigger effect than is currently believed or that "we are still missing 94 percent of the genes," says Atul Butte, MD, PhD, an assistant professor of pediatrics at Stanford University.

Threshold for diagnosis of diabetes is based on the relationship between results of glucose tolerance tests, fasting glucose or HbA1c and complications such as retinal problems.[10] A fasting or random blood sugar is preferred over the glucose tolerance test, as they are more convenient for people.[10] HbA1c has the advantages that fasting is not required and results are more stable but has the disadvantage that the test is more costly than measurement of blood glucose.[50] It is estimated that 20% of people with diabetes in the United States do not realize that they have the disease.[10]

The 1989 "St. Vincent Declaration"[117][118] was the result of international efforts to improve the care accorded to those with diabetes. Doing so is important not only in terms of quality of life and life expectancy but also economically – expenses due to diabetes have been shown to be a major drain on health – and productivity-related resources for healthcare systems and governments.
Because people with type 2 diabetes produce some insulin, ketoacidosis does not usually develop even when type 2 diabetes is untreated for a long time. Rarely, the blood glucose levels become extremely high (even exceeding 1,000 mg/dL). Such high levels often happen as the result of some superimposed stress, such as an infection or drug use. When the blood glucose levels get very high, people may develop severe dehydration, which may lead to mental confusion, drowsiness, and seizures, a condition called hyperosmolar hyperglycemic state. Currently, many people with type 2 diabetes are diagnosed by routine blood glucose testing before they develop such severely high blood glucose levels.
Diabetes mellitus is a chronic disease caused by inherited and/or acquired deficiency in production of insulin by the pancreas, or by the ineffectiveness of the insulin produced. Such a deficiency results in increased concentrations of glucose in the blood, which in turn damage many of the body's systems, in particular the blood vessels and nerves.
John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.

A second oral agent of another class or insulin may be added if metformin is not sufficient after three months.[76] Other classes of medications include: sulfonylureas, thiazolidinediones, dipeptidyl peptidase-4 inhibitors, SGLT2 inhibitors, and glucagon-like peptide-1 analogs.[76] As of 2015 there was no significant difference between these agents.[76] A 2018 review found that SGLT2 inhibitors may be better than glucagon-like peptide-1 analogs or dipeptidyl peptidase-4 inhibitors.[92]
Jump up ^ Seida, Jennifer C.; Mitri, Joanna; Colmers, Isabelle N.; Majumdar, Sumit R.; Davidson, Mayer B.; Edwards, Alun L.; Hanley, David A.; Pittas, Anastassios G.; Tjosvold, Lisa; Johnson, Jeffrey A. (Oct 2014). "Effect of Vitamin D3 Supplementation on Improving Glucose Homeostasis and Preventing Diabetes: A Systematic Review and Meta-Analysis". The Journal of Clinical Endocrinology & Metabolism. 99 (10): 3551–60. doi:10.1210/jc.2014-2136. PMC 4483466. PMID 25062463.
People with T2D produce insulin, but their bodies don’t use it correctly; this is referred to as being insulin resistant. People with type 2 diabetes may also be unable to produce enough insulin to handle the glucose in their body. In these instances, insulin is needed to allow the glucose to travel from the bloodstream into our cells, where it’s used to create energy.

Retinopathy: If blood sugar levels are too high, they can damage the eyes and cause vision loss and blindness. Retinopathy causes the development and leaking of new blood vessels behind the eye. Other effects of diabetes, such as high blood pressure and high cholesterol, can make this worse. According to the CDC, early treatment can prevent or reduce the risk of blindness in an estimated 90 percent of people with diabetes.

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.
Your risk for Type 2 diabetes increases as you get older. It also increases if you smoke. Although smoking doesn't cause diabetes per se, the negative effects on your health are enough to make it more likely that Type 2 diabetes will occur if you have the other risk factors. "We try to be aggressive with smoking cessation, in particular in patients with diabetes," says Dr. Asha M. Thomas, an endocrinologist with Sinai Hospital of Baltimore.
Type 2 diabetes is most common is those who are genetically predisposed and who are overweight, lead a sedentary lifestyle, have high blood pressure, and/or have insulin resistance due to excess weight. People of certain ethnicities are more likely to develop diabetes, too. These include: African Americans, Mexican Americans, American Indians, Native Hawaiians, Pacific Islanders, and Asian Americans. These populations are more likely to be overweight and have high blood pressure, which increases the risk of developing diabetes.
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.

Endocrinology A chronic condition which affects ±10% of the general population, characterized by ↑ serum glucose and a relative or absolute ↓ in pancreatic insulin production, or ↓ tissue responsiveness to insulin; if not properly controlled, the excess glucose damages blood vessels of the eyes, kidneys, nerves, heart Types Insulin dependent–type I and non-insulin dependent–type II diabetes Symptoms type 1 DM is associated with ↑ urine output, thirst, fatigue, and weight loss (despite an ↑ appetite), N&V; type 2 DM is associated with, in addition, non-healing ulcers, oral and bladder infections, blurred vision, paresthesias in the hands and feet, and itching Cardiovascular MI, stoke Eyes Retinal damage, blindness Legs/feet Nonhealing ulcers, cuts leading to gangrene and amputation Kidneys HTN, renal failure Neurology Paresthesias, neuropathy Diagnosis Serum glucose above cut-off points after meals or when fasting; once therapy is begun, serum levels of glycosylated Hb are measured periodically to assess adequacy of glucose control Management Therapy reflects type of DM; metformin and triglitazone have equal and additive effects on glycemic control Prognosis A function of stringency of glucose control and presence of complications. See ABCD Trial, Brittle diabetes, Bronze diabetes, Chemical diabetes, Gestational diabetes, Insulin-dependent diabetes, Metformin, MODY diabetes, Nephrogenic diabetes insipidus, Non-insulin-dependent diabetes mellitus, Pseudodiabetes, Secondary diabetes, Starvation diabetes, Troglitazone.
It is recommended that all people with type 2 diabetes get regular eye examination.[13] There is weak evidence suggesting that treating gum disease by scaling and root planing may result in a small short-term improvement in blood sugar levels for people with diabetes.[79] There is no evidence to suggest that this improvement in blood sugar levels is maintained longer than 4 months.[79] There is also not enough evidence to determine if medications to treat gum disease are effective at lowering blood sugar levels.[79]
Type 1 and type 2 diabetes were identified as separate conditions for the first time by the Indian physicians Sushruta and Charaka in 400–500 AD with type 1 associated with youth and type 2 with being overweight.[110] The term "mellitus" or "from honey" was added by the Briton John Rolle in the late 1700s to separate the condition from diabetes insipidus which is also associated with frequent urination.[110] Effective treatment was not developed until the early part of the 20th century when the Canadians Frederick Banting and Charles Best discovered insulin in 1921 and 1922.[110] This was followed by the development of the long acting NPH insulin in the 1940s.[110]
a complex disorder of carbohydrate, fat, and protein metabolism that is primarily a result of a deficiency or complete lack of insulin secretion by the beta cells of the pancreas or resistance to insulin. The disease is often familial but may be acquired, as in Cushing's syndrome, as a result of the administration of excessive glucocorticoid. The various forms of diabetes have been organized into categories developed by the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus of the American Diabetes Association. Type 1 diabetes mellitus in this classification scheme includes patients with diabetes caused by an autoimmune process, dependent on insulin to prevent ketosis. This group was previously called type I, insulin-dependent diabetes mellitus, juvenile-onset diabetes, brittle diabetes, or ketosis-prone diabetes. Patients with type 2 diabetes mellitus are those previously designated as having type II, non-insulin-dependent diabetes mellitus, maturity-onset diabetes, adult-onset diabetes, ketosis-resistant diabetes, or stable diabetes. Those with gestational diabetes mellitus are women in whom glucose intolerance develops during pregnancy. Other types of diabetes are associated with a pancreatic disease, hormonal changes, adverse effects of drugs, or genetic or other anomalies. A fourth subclass, the impaired glucose tolerance group, also called prediabetes, includes persons whose blood glucose levels are abnormal although not sufficiently above the normal range to be diagnosed as having diabetes. Approximately 95% of the 18 million diabetes patients in the United States are classified as type 2, and more than 70% of those patients are obese. About 1.3 million new cases of diabetes mellitus are diagnosed in the United States each year. Contributing factors to the development of diabetes are heredity; obesity; sedentary life-style; high-fat, low-fiber diets; hypertension; and aging. See also impaired glucose tolerance, potential abnormality of glucose tolerance, previous abnormality of glucose tolerance.
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.

Can type 2 diabetes be prevented? It is possible to reduce the risk of developing type 2 diabetes, although the underlying risk of type 2 diabetes depends strongly on genetic factors. But there was less type 2 diabetes around some years ago when people had a more active life and didn’t eat a modern Western diet. So it is fair to say that risk of getting type 2 diabetes is based on a genetic predisposition that is aggravated by lifestyle. Type 2 diabetes is associated with obesity, as well as a variety of environmental factors. To lower the risk of developing type 2 diabetes (as well as other diseases), it is highly recommended to exercise often, eat healthily, and maintain a healthy weight. 
It is especially important that persons with diabetes who are taking insulin not skip meals; they must also be sure to eat the prescribed amounts at the prescribed times during the day. Since the insulin-dependent diabetic needs to match food consumption to the available insulin, it is advantageous to increase the number of daily feedings by adding snacks between meals and at bedtime.
Women seem to be at a greater risk as do certain ethnic groups,[10][107] such as South Asians, Pacific Islanders, Latinos, and Native Americans.[23] This may be due to enhanced sensitivity to a Western lifestyle in certain ethnic groups.[108] Traditionally considered a disease of adults, type 2 diabetes is increasingly diagnosed in children in parallel with rising obesity rates.[10] Type 2 diabetes is now diagnosed as frequently as type 1 diabetes in teenagers in the United States.[13]
Retinopathy: If blood sugar levels are too high, they can damage the eyes and cause vision loss and blindness. Retinopathy causes the development and leaking of new blood vessels behind the eye. Other effects of diabetes, such as high blood pressure and high cholesterol, can make this worse. According to the CDC, early treatment can prevent or reduce the risk of blindness in an estimated 90 percent of people with diabetes.
When you have type 2 diabetes, your cells don't get enough glucose, which may cause you to lose weight. Also, if you are urinating more frequently because of uncontrolled diabetes, you may lose more calories and water, resulting in weight loss, says Daniel Einhorn, MD, medical director of the Scripps Whittier Diabetes Institute and clinical professor of medicine at the University of California in San Diego.