Insulin is a hormone produced in the pancreas by special cells, called beta cells. The pancreas is below and behind the stomach. Insulin is needed to move blood sugar (glucose) into cells. Inside the cells, glucose is stored and later used for energy.

When you have type 2 diabetes, your fat, liver, and muscle cells do not respond correctly to insulin. This is called insulin resistance. As a result, blood sugar does not get into these cells to be stored for energy.

When sugar cannot enter cells, a high level of sugar builds up in the blood. This is called hyperglycemia.

Type 2 diabetes usually occurs slowly over time. Most people with the disease are overweight or obese when they are diagnosed. Increased fat makes it harder for your body to use insulin the correct way.

Type 2 diabetes can also develop in people who are thin. This is more common in the elderly.

Family history and genes play a role in type 2 diabetes. Low activity level, poor diet, and excess body weight around the waist increase your chance of getting the disease.

People with type 2 diabetes often have no symptoms at first. They may not have symptoms for many years.

Early symptoms of diabetes may include:

• Bladder, kidney, skin, or other infections that are more frequent or heal slowly
• Fatigue
• Hunger
• Increased thirst
• Increased urination

The first symptom may also be:

• Blurred vision
• Erectile dysfunction
• Pain or numbness in the feet or hands