Then, your blood sugar levels get too high. High blood sugar can have a deleterious effect on many parts of your body, including heart, blood vessels, nerves, eyes, and kidneys. Those who are overweight, don’t exercise enough, or have a history of type 2 diabetes in their family are more likely to get the disease. Maintaining a healthy weight, eating a healthy diet, and getting enough exercise can prevent type 2 diabetes. If you have a history of diabetes in your family, or if you are overweight, stay ahead of the disease by making healthy lifestyle choices and changing your diet.
The World Health Organization recommends testing those groups at high risk[54] and in 2014 the USPSTF is considering a similar recommendation.[58] High-risk groups in the United States include: those over 45 years old; those with a first degree relative with diabetes; some ethnic groups, including Hispanics, African-Americans, and Native-Americans; a history of gestational diabetes; polycystic ovary syndrome; excess weight; and conditions associated with metabolic syndrome.[23] The American Diabetes Association recommends screening those who have a BMI over 25 (in people of Asian descent screening is recommended for a BMI over 23).[59]
DKA usually follows increasing hyperglycemia and symptoms of osmotic diuresis. Users of insulin pumps, by virtue of absent reservoirs of subcutaneous insulin, may present with ketosis and more normal blood glucose levels. They are more likely to present with nausea, vomiting, and abdominal pain, symptoms similar to food poisoning. DKA may manifest as respiratory distress.

Blood glucose levels: persistently elevated blood sugar levels are diagnostic of diabetes mellitus. A specific test called a glucose tolerance test (GTT) may be performed. For this you need to be fasted and will be given a sugary drink. Your glucose level will then be measured at one and two hours after the doseto determine how welll your body copes with glucose.
There are some interesting developments in blood glucose monitoring including continuous glucose sensors. The new continuous glucose sensor systems involve an implantable cannula placed just under the skin in the abdomen or in the arm. This cannula allows for frequent sampling of blood glucose levels. Attached to this is a transmitter that sends the data to a pager-like device. This device has a visual screen that allows the wearer to see, not only the current glucose reading, but also the graphic trends. In some devices, the rate of change of blood sugar is also shown. There are alarms for low and high sugar levels. Certain models will alarm if the rate of change indicates the wearer is at risk for dropping or rising blood glucose too rapidly. One version is specifically designed to interface with their insulin pumps. In most cases the patient still must manually approve any insulin dose (the pump cannot blindly respond to the glucose information it receives, it can only give a calculated suggestion as to whether the wearer should give insulin, and if so, how much). However, in 2013 the US FDA approved the first artificial pancreas type device, meaning an implanted sensor and pump combination that stops insulin delivery when glucose levels reach a certain low point. All of these devices need to be correlated to fingersticks measurements for a few hours before they can function independently. The devices can then provide readings for 3 to 5 days.
1. Monitoring of blood glucose status. In the past, urine testing was an integral part of the management of diabetes, but it has largely been replaced in recent years by self monitoring of blood glucose. Reasons for this are that blood testing is more accurate, glucose in the urine shows up only after the blood sugar level is high, and individual renal thresholds vary greatly and can change when certain medications are taken. As a person grows older and the kidney is less able to eliminate sugar in the urine, the renal threshold rises and less sugar is spilled into the urine. The position statement of the American Diabetes Association on Tests of Glycemia in Diabetes notes that urine testing still plays a role in monitoring in type 1 and gestational diabetes, and in pregnancy with pre-existing diabetes, as a way to test for ketones. All people with diabetes should test for ketones during times of acute illness or stress and when blood glucose levels are consistently elevated.
Type 2 diabetes usually begins with insulin resistance, a condition in which muscle, liver, and fat cells do not use insulin well. As a result, your body needs more insulin to help glucose enter cells. At first, the pancreas makes more insulin to keep up with the added demand. Over time, the pancreas can’t make enough insulin, and blood glucose levels rise.
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.
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]
People with these risk factors should be screened for diabetes at least once every three years. Diabetes risk can be estimated using online risk calculators. Doctors may measure fasting blood glucose levels and hemoglobin A1C level, or do an oral glucose tolerance test. If the test results are on the border between normal and abnormal, doctors do the screening tests more often, at least once a year.
Diet, exercise, and education are the cornerstones of treatment of diabetes and often the first recommendations for people with mild diabetes. Weight loss is important for people who are overweight. People who continue to have elevated blood glucose levels despite lifestyle changes, or have very high blood glucose levels and people with type 1 diabetes (no matter their blood glucose levels) also require drugs.
Originally described in approximately 30% of patients with type 1 diabetes mellitus, limited joint mobility occurs in 50% of patients older than age 10 years who have had diabetes for longer than 5 years. The condition restricts joint extension, making it difficult to press the hands flat against each other. The skin of patients with severe joint involvement has a thickened and waxy appearance.
Diabetes can also be diagnosed if a blood glucose level taken any time of the day without regards to meals is 11.1 mmol/L or higher, plus you have symptoms characteristic of diabetes (e.g., increase thirst, increase urination, unexplained weight loss). A doctor may also examine the eyes for signs of damage to the blood vessels of the retina (back of the eye). Finally, diabetes mellitus is diagnosed if the 3-month cumulative blood sugar average test, known as hemoglobin A1C or glycated hemoglobin, is 6.5% or higher.
High blood glucose sets up a domino effect of sorts within your body. High blood sugar leads to increased production of urine and the need to urinate more often. Frequent urination causes you to lose a lot of fluid and become dehydrated. Consequently, you develop a dry mouth and feel thirsty more often. If you notice that you are drinking more than usual, or that your mouth often feels dry and you feel thirsty more often, these could be signs of type 2 diabetes.