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]

Pre-clinical diabetes refers to the time during which destruction of pancreatic insulin-producing cells is occurring, but symptoms have not yet developed. This period may last for months to years. Normally, 80-90% of the pancreatic beta cells must be destroyed before any symptoms of diabetes develops. During this time, blood tests can identify some immunological markers of pancreatic cell destruction. However, there is currently no known treatment to prevent progression of pre-clinical diabetes to true diabetes mellitus.
Older people may have a difficult time adding exercise to their daily life, particularly if they have not been active or if they have a disorder that limits their movement, such as arthritis. However, they may be able to add exercise to their usual routine. For example, they can walk instead of drive or climb the stairs instead of take the elevator. Also, many community organizations offer exercise programs designed for older people.
As of 2015, an estimated 415 million people had diabetes worldwide,[8] with type 2 DM making up about 90% of the cases.[16][17] This represents 8.3% of the adult population,[17] with equal rates in both women and men.[18] As of 2014, trends suggested the rate would continue to rise.[19] Diabetes at least doubles a person's risk of early death.[2] From 2012 to 2015, approximately 1.5 to 5.0 million deaths each year resulted from diabetes.[8][9] The global economic cost of diabetes in 2014 was estimated to be US$612 billion.[20] In the United States, diabetes cost $245 billion in 2012.[21]
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).
In this health topic, we discuss hyperglycemic hyperosmolar nonketotic syndrome (HHNS), an extremely serious complication that can lead to diabetic coma and even death in type 2 diabetes. This serious condition occurs when the blood sugar gets too high and the body becomes severely dehydrated. To prevent HHNS and diabetic coma in type 2 diabetes, check your blood sugar regularly as recommended by your health care provider; check your blood sugar more frequently when you are sick, drink plenty of fluids, and watch for signs of dehydration.