Follow Our Live Coverage of COVID-19 Developments


Diseases and conditions are any form of illness that disrupts normal bodily functions and leaves a person feeling impaired in some way. There are thousands of different kinds of diseases and conditions, and they can range in severity from a mild cold to a life-threatening heart condition. Sometimes they are caused by an outside organism like a virus or bacteria. Other times, the body attacks itself in the form of an autoimmune disorder. Many diseases and conditions have a cause that is not known or is poorly understood.

Types of Diseases

Some diseases and conditions are defined as acute. This essentially means that they are short-term diseases or conditions that only last a few days or a few weeks. Sometimes acute conditions can be treated with medication, while others will subside on their own over time.

The more concerning types of diseases and conditions are generally chronic illnesses. These are diseases and conditions that last a long time, and they often have no cure. According to the U.S. Centers for Disease Control and Prevention, seven out of every 10 deaths in the United States is due to a chronic disease. The most common chronic diseases are heart disease, cancer and stroke. Together, these three chronic diseases account for about half of all deaths in the United States. Diabetes and arthritis are other common chronic health conditions. Many of these are preventable with healthy lifestyle choices, and they can often be managed after they occur even if there is no cure.

The Changing Definition of Disease

Disease definitions tend to change through the years. For example, the bone condition osteoporosis was not formally identified as a disease until 1994. The definition of what is a disease or a condition continues to evolve along with the general understanding of medicine and health.

SOURCES: Biology Online; U.S. Centers for Disease Control and Prevention; The European Molecular Biology Organization.

Sources:Disease, Biology Online, 2008,, Accessed 9/17/13.Mission, Role and Pledge, CDC, 2013,, Accessed 9/17/13.Chronic Diseases and Health Promotion, CDC, 2012,, Accessed 9/17/13.What Is a Disease?, Embo Reports, 2004,, Accessed 9/17/13.

diseases and conditions Topics in the News