WASHINGTON -- The government says nearly 16 million people with a condition known as "pre-diabetes" should be tested so they can take steps to prevent full-blown diabetes.

Health and Human Services Secretary Tommy Thompson says those diagnosed with it will likely develop diabetes within a decade unless they do something about it.

He told a news conference that diet and exercise can at least delay, if not completely prevent, type 2 diabetes from striking.

"We want people to know that pre-diabetes is a serious condition that can be reversed or alleviated with modest changes in their daily routines -- such as eating fewer calories and walking regularly for exercise," Thompson said.

Doctors have long known that a condition called "impaired glucose tolerance" indicates a risk of diabetes. The government has renamed the condition "pre-diabetes" to make it easier for people to understand.

"About 16 million people in the country have pre-diabetes and most of them don't know it," said Dr. Judith Fradkin of the National Institute of Diabetes & Digestive & Kidney Diseases, which is part of the National Institutes of Health.

The guidelines recommend that everyone 45 or older -- particularly those who are overweight -- consider getting tested.

And they say doctors should consider testing younger adults if they are significantly overweight and have another risk -- such as a diabetic relative or bad cholesterol.

Thompson also released an updated estimate showing 17 million Americans suffer from diabetes -- an increase of 8 percent from the most commonly used previous estimate. The new estimate is based on population changes in the most recent U.S. census.

Diabetes is a leading cause of blindness, kidney failure, amputations and heart disease. The disease kills 180,000 people in the United States each year.