Chronic diseases are prolonged conditions that often do not improve and are rarely cured completely. They are also the leading causes of death and disability in the United States. These diseases account for seven of every 10 deaths and affect the quality of life of 90 million Americans. Heart disease, arthritis, cancer, diabetes, hepatitis, and asthma are examples of chronic diseases.

In 2001, chronic disease accounted for more than two-thirds of all deaths in the United States.  The five leading fatal chronic diseases are diseases of the heart, cancers, stroke, chronic lower respiratory disease and diabetes.  In 2004, chronic diseases affected the lives of countless Nevadans, and the five leading chronic diseases claimed the lives of 11,090 citizens of this state. This accounts for nearly 63% of all the deaths in Nevada for
that year.

There are many underlying causes of chronic diseases. There is mounting evidence that communicable agents arid genetic factors may be involved in a variety of chronic diseases. Viruses, for example, have been implicated as causes of some cancers (liver cancer is linked to hepatitis B virus infection; cervical cancer is linked to sexually transmitted viruses), and bacteria (H pylori) have been shown to cause stomach ulcers. Some cases of female breast cancer have been linked to genetic defects (though this is a small minority of cases).

The prevention of chronic diseases, however, does not generally target either infectious agents or genetic factors. Lifestyle choices and behaviors continue to dominate the causes of chronic disease. The most effective prevention programs are aimed at known lifestyle risk factors such as tobacco use, physical inactivity, and poor nutrition. These efforts are effective in lowering rates of chronic disease.

Eating nutritious foods, becoming more physically active, and avoiding tobacco can help keep you from developing many of these diseases and conditions. And, even if you already have diabetes, heart disease, arthritis or another chronic condition, eating more healthful food and getting more exercise, whether it's a brisk walk, a bike ride, a jog or a swim, can help you better manage your illness, avoid complications and prolong your life.

Chronic illness has a profound effect on the physical, emotional and mental well-being of individuals, often making it difficult to carryon with daily routines and relationships: However, in many cases, deterioration in health can be minimized by good care. This often depends upon individual choices made on a daily basis.