Type 2 diabetes is an impairment in the way the body regulates and uses sugar (glucose) as a fuel. This long-term (chronic) condition results in too much sugar circulating in the bloodstream. Eventually, high blood sugar levels can lead to disorders of the circulatory, nervous and immune systems.
In type 2 diabetes, there are primarily two interrelated problems at work. Your pancreas does not produce enough insulin — a hormone that regulates the movement of sugar into your cells — and cells respond poorly to insulin and take in less sugar.
Type 2 diabetes used to be known as adult-onset diabetes, but both type 1 and type 2 diabetes can begin during childhood and adulthood. Type 2 is more common in older adults, but the increase in the number of children with obesity has led to more cases of type 2 diabetes in younger people.
There’s no cure for type 2 diabetes, but losing weight, eating well and exercising can help you manage the disease. If diet and exercise aren’t enough to manage your blood sugar, you may also need diabetes medications or insulin therapy.
Signs and symptoms of type 2 diabetes often develop slowly. In fact, you can be living with type 2 diabetes for years and not know it. When signs and symptoms are present, they may include:
- Increased thirst
- Frequent urination
- Increased hunger
- Unintended weight loss
- Blurred vision
- Slow-healing sores
- Frequent infections
- Numbness or tingling in the hands or feet
- Areas of darkened skin, usually in the armpits and neck
Type 2 diabetes is primarily the result of two interrelated problems:
- Cells in muscle, fat and the liver become resistant to insulin. Because these cells don’t interact in a normal way with insulin, they don’t take in enough sugar.
- The pancreas is unable to produce enough insulin to manage blood sugar levels.
Exactly why this happens is unknown, but being overweight and inactive are key contributing factors.
Factors that may increase your risk of type 2 diabetes include:
- Being overweight or obese is a main risk.
- Fat distribution. Storing fat mainly in your abdomen — rather than your hips and thighs — indicates a greater risk. Your risk of type 2 diabetes rises if you’re a man with a waist circumference above 40 inches (101.6 centimeters) or a woman with a measurement above 35 inches (88.9 centimeters).
- The less active you are, the greater your risk. Physical activity helps control your weight, uses up glucose as energy and makes your cells more sensitive to insulin.
- Family history. The risk of type 2 diabetes increases if your parent or sibling has type 2 diabetes.
- Race and ethnicity. Although it’s unclear why, people of certain races and ethnicities — including Black, Hispanic, Native American and Asian people, and Pacific Islanders — are more likely to develop type 2 diabetes than white people are.
- Blood lipid levels. An increased risk is associated with low levels of high-density lipoprotein (HDL) cholesterol — the “good” cholesterol — and high levels of triglycerides.
- The risk of type 2 diabetes increases as you get older, especially after age 45.
- Prediabetes is a condition in which your blood sugar level is higher than normal, but not high enough to be classified as diabetes. Left untreated, prediabetes often progresses to type 2 diabetes.
- Pregnancy-related risks. Your risk of developing type 2 diabetes increases if you developed gestational diabetes when you were pregnant or if you gave birth to a baby weighing more than 9 pounds (4 kilograms).
- Polycystic ovary syndrome. Having polycystic ovary syndrome — a common condition characterized by irregular menstrual periods, excess hair growth and obesity — increases the risk of diabetes
- Areas of darkened skin, usually in the armpits and neck. This condition often indicates insulin resistance.
The prevalence of diabetes has increased worldwide mainly as a result of the obesity epidemic. The current treatment of type 2 diabetes is aimed at increasing insulin secretion, decreasing glucose absorption from the small intestine or improving insulin sensitivity. Tight glycemic control can reduce some of the complications of diabetes; however, this goal is often unattainable partly because of poor patient compliance, inadequate health care delivery, and the high cost of therapy.