Type 2 diabetes, the most common type of diabetes, is a disease that occurs when your blood glucose, also called blood sugar, is too high.

In type 2 diabetes, your body doesn’t make enough insulin or doesn’t use insulin well. Too much glucose then stays in your blood, and not enough reaches your cells.

You can develop type 2 diabetes at any age, even during childhood. However, type 2 diabetes occurs most often in middle-aged and older people. You are more likely to develop type 2 diabetes if you are age 45 or older, have a family history of diabetes, or are overweight or obese. Diabetes is more common in people who are African American, Hispanic/Latino, American Indian, Asian American, or Pacific Islander.

Physical inactivity and certain health problems such as high blood pressure affect your chances of developing type 2 diabetes. You are also more likely to develop type 2 diabetes if you have prediabtes or had gestational diabetes when you were pregnant.

Symptoms of diabetes include

• increased thirst and urination
• increased hunger
• feeling tired
• blurred vision
• numbness or tingling in the feet or hands
• sores that do not heal
• unexplained weight loss

Symptoms of type 2 diabetes often develop slowly—over the course of several years—and can be so mild that you might not even notice them. Many people have no symptoms. Some people do not find out they have the disease until they have diabetes-related health problems, such as blurred vision or heart disease.

Type 2 diabetes usually begins with insulin resistance, a condition in which muscle, liver and fat cells do not use insulin well. As a result, your body needs more insulin to help glucose enter cells. At first, the pancreas makes more insulin to keep up with the added demand. Over time, the pancreas can’t make enough insulin, and blood glucose levels rise.