You could have prediabetes and not even know it. More than one in three adult Americans—approximately 88 million—have the condition, but 90% don't realize it.

Recent research by the Centers for Disease Control and Prevention also reports that nearly one in four young adults (ages 19 to 34) and half of people over the age of 65 are living with prediabetes.

What is prediabetes? And if so many people don't realize they have it, what can you do—especially if diabetes runs in your family?

Prediabetes means your blood sugar levels are higher than normal. The levels are not high enough to be diagnosed as type 2 diabetes, but it's a warning sign that, over time, you could develop the disease. That's why learning about risk factors is so important.

Eating healthier food and becoming more physically active can help you lose weight, feel better, and lower your risk of developing type 2 diabetes.

Prediabetes indicates a problem with the cells in your body. It means that those cells are not responding in a normal way to insulin, an important hormone that helps sugar in the blood get into cells and be used for energy. If a person’s body can’t make or respond to insulin, blood sugar levels rise.

Certain factors can make you more likely to develop prediabetes. You are more at risk if you have a parent or sibling with diabetes and are age 45 or older. Race and ethnicity are also factors: African Americans, Hispanic/Latino Americans, Native Americans, and some Asian Americans are at higher risk for type 2 diabetes. Additionally, you're more at risk if you are overweight or obese and are physically inactive. This is just a short list of risk factors. To see more and to take a test to learn about your own risk factors, visit the National Institute of Diabetes and Digestive and Kidney Diseases website.

Getting more exercise and losing a small amount of weight can help prevent diabetes if you are at risk. Eating healthier food and becoming more physically active—taking a brisk walk for 30 minutes a day, five times a week, for example—can help you lose weight, feel better, and lower your risk of developing type 2 diabetes. Even small steps—losing just 5% to 7% of your body weight (10 to 14 pounds for a 200-pound person)—can make a big difference in preventing type 2 diabetes.