Non-infectious diseases (also called Non-communicable diseases) are those diseases that are not caused by a pathogen and cannot be shared from one person to another. Disease caused by these organisms are infectious diseases. There are many kinds of non-infectious diseases.
Non-infectious diseases may be caused by either the environment, nutritional deficiencies, lifestyle choices, or genetic inheritances. Unlike infectious diseases, non-infectious diseases are not communicable or contagious, although some kinds can be passed down genetically to the children of a carrier.
Historically, infectious diseases were the main cause of death in the world and, indeed, in some developing regions this may still be the case. With the development of antibiotics and vaccination programs, infectious disease is no longer the leading cause of death in the western world. Non-infectious disease is now responsible for the leading causes of death in both developed and some developing countries.
Some medical conditions are not infectious in nature, but are also not normally classified with non-infectious diseases. These include some types of physiological malfunction, some mental illnesses, and some conditions that are not classically considered "diseases", such as substance abuse, ageing and obesity.
.Noncommunicable diseases are usually thought of as chronic conditions that do not result from an acute infectious process. These conditions cause death, dysfunction, or impairment in the quality of life, and they usually develop over relatively long periods—at first without causing symptoms; but after disease manifestations develop, there may be a protracted period of impaired health. Generally, these conditions or diseases result from prolonged exposure to causative agents, many associated with personal behaviors and environmental factors. The major noncommunicable diseases are heart disease, cancer, asthma, diabetes, allergies, stroke, and more....