Diabetes mellitus type 2 – formerly non-insulin-dependent diabetes mellitus (NIDDM) or adult-onset diabetes – is a metabolic disorder that is characterized by high blood glucose in the context of insulin resistance and relative insulin deficiency. The classic symptoms are excess thirst, frequently having to urinate, and constant hunger. Type 2 diabetes makes up about 90% of cases of diabetes with the other 10% due primarily to diabetes mellitus type 1 and gestational diabetes. Obesity is the primary cause of type 2 diabetes in people who are genetically predisposed to the disease.
Type 2 diabetes is initially managed by increasing exercise and dietary modification. If blood sugars are not lowered by these measures, medications such as metformin or insulin may be needed. In those on insulin there is typically the requirement to routinely check blood sugar levels.
Rates of diabetes have increased markedly over the last 50 years in parallel with obesity. As of 2010 there are approximately 285 million people with the disease compared to around 30 million in 1985. Long-term complications from high blood sugar can include heart attacks, strokes, diabetic retinopathy where eye sight is affected, kidney failure which may require dialysis, and poor circulation of limbs leading to amputations. The acute complication ketoacidosis is uncommon unlike in type 1 diabetes, nonketonic hyperglycemia however may occur.