CHARLOTTESVILLE, Va. — Heart disease, diabetes, cancer, arthritis — the words drift around us daily. Yet usually it's not until a close friend, relative or we ourselves contract one of these chronic diseases that we really reflect on the destruction they wreak.

Chronic diseases are those that persist for a long time and can't be prevented by vaccines or easily cured by medications. These diseases hang on and most often worsen with time.

As the chief of a busy endocrinology and metabolism program at the University of Virginia, I witness the health complications related to progression of diabetes, and the heart-rending toll it takes on patients and families. The economic consequences of diabetes and other chronic diseases are equally alarming. Consider just a few of the sobering statistics:

n The medical care costs of people with chronic diseases account for more than 75 percent of the nation's $1.4 trillion medical care costs.

n More than 90 million Americans live with chronic illnesses. Chronic diseases account for one-third of the years of potential life lost before age 65, and they account for 70 percent of all deaths in the United States.

n Arthritis alone results in estimated medical care costs of more than $22 billion annually, and that increases to almost $82 billion when you add in lost productivity. The direct and indirect costs of diabetes are even higher — nearly $132 billion a year.

The good news for many sufferers of chronic diseases is that there are numerous solutions close at hand — simple lifestyle changes that can help to slow down or even reverse some of the considerable damage.

Diabetes is one of the best examples of both the problems stemming from a chronic disease, and the treatments that can make a real, measurable difference in a patient's health, greatly delaying the ravaging effect of the diseases — and keeping workers on the job longer while living healthier lives.

Type 1 diabetes, the more severe form, is an autoimmune disease caused when the body turns on itself and begins to destroy its own islet cells. Type 2 diabetes is caused by a reduction in insulin's ability to lower blood sugar and thwart islet cell destruction in the pancreas due to inflammation.

About 21 million Americans — a staggering 7 percent of the population — have been diagnosed with diabetes, and an additional 16 million are at risk. Both forms of diabetes can lead to severe complications or death due to damage to the heart, blood vessels, kidneys, eyes and nerves.

Despite this, large numbers of diabetics are turning things around. Type 1 diabetes patients are taking on imposing physical challenges and winning.

A recent New York Times article noted that many have become "ultra-athletes" thanks to new technology, the emergence of companies that help them manage their illness, the rise of successful role models and sheer determination. Rather than accepting their fates, they are running marathons, completing 100-mile bike rides, and even participating in grueling Ironman triathlons — often with their doctor's blessing.

Type 2 diabetes is intertwined with the increasing problem of obesity — both here and in many other countries. Shedding weight in a healthy program of controlled nutrition plus exercise has allowed some patients to stop taking prescribed medications. Bariatric surgery — a form of weight loss surgery for very obese patients — also can lead patients to increasingly lower doses of medication or no need for these drugs.

And recent research shows that losing weight and engaging in physical activity also reduces the incidence of inflammation-related genes in the fatty tissue of obese people — an especially important finding because inflammation in the pancreas can result in diabetes.

Overall, we can reduce the effects of diabetes and the other bedeviling chronic diseases by simply taking some time to think.

Think about what you put in your mouth, for instance. Avoid foods high in trans or saturated fats, or another cigarette or a beer. Eat a bit better than you did yesterday, adding foods like leafy green vegetables, whole grains high in magnesium and heart-healthy forms of fats such as fish oil and olive oil to your daily diet.

Think about moving more. Get up and exercise. Walk a few minutes today and walk a few more minutes tomorrow.

Patients often can overcome their chronic diseases, but preventing them in the first place with a regimen of good diet and nutrition is the wisest choice.

Jerry Nadler is the Crispell professor of medicine and chief of the University of Virginia Division of Endocrinology and Metabolism.