Type 2 diabetes is marked by both insulin resistance (the body is resistant to the insulin it produces)and insulin deficiency (the body produces some insulin, but not enough to overcome insulin resistance). Since insulin is unable to transport sugar (glucose) to the body's cells for use as energy, glucose levels in the blood become elevated. Over time, high blood glucose can lead to serious complications of diabetes like retinopathy, neuropathy, and heart disease. There is no cure for diabetes, but complications can be prevented or delayed thanks to treatment focused on controlling blood glucose levels with a healthy diet, regular exercise, oral medications, and insulin when required. People with type 2 diabetes are also at an elevated risk for cardiovascular disease. For this reason, adequate treatment for elevated blood pressure and cholesterol levels—both of which increase a person's risk for heart attack and stroke—is essential.
Unlike type 1 diabetes, type 2 diabetes typically occurs in middle-aged and older adults, although an alarmingly high percentage of new cases are seen in adolescents and young adults. Many people who develop type 2 diabetes are overweight or obese. A family history, especially in first-degree relatives, also increases the risk for developing type 2 diabetes. In the United States, it is estimated that 23.6 million people have diabetes, and about 20 percent of those remain undiagnosed. Type 2 diabetes represents about 90 to 95 percent of cases of diagnosed diabetes. People of African American, Hispanic, or Native American origin have a greater risk of developing type 2 diabetes than whites. Some symptoms of type 2 diabetes are excess thirst, frequent urination, blurry vision, fatigue, and recurrent skin and urinary tract infections.