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. Noncommunicable diseases are the leading cause of functionary impairment and death worldwide.
These conditions have been the leading cause of death in the United States and other high-income countries over the last fifty years, and they are emerging as a leading cause of death in low-to middle-income countr CAUSES AND PREVENTION he causes of noncommunicable diseases are often divided into modifiable nonmodifiable factors genetically inherited diseases and environmental diseases Modifiable Causes. The causes of noncommunicable diseases are often divided into modifiableand nonmodifiable factors, although these distinctions are blurring with greater knowledge.
Chronic diseases result from genetic, behavioral, and environmental factors and the interactions between them. These factors, generally termed “risk factors,” produce molecular and structural changes in organs and tissues but produce few if any early symptoms or signs of disease. After relatively long periods of time, usually decades, disease manifestations and impairment of health result. Risk factors place an individual at a greater likelihood of developing disease, but do not predict disease with absolute certainty. For most chronic diseases, several risk factors contribute.
Nonmodifiable Causes. A major nonmodifiable individual risk for disease is genetic susceptibility. This has a very important influence on disease development, but does not confer an absolute certainty that a disease will occur. In the overwhelming majority of diseases, inherited susceptibility interacts either adversely or beneficially with environmental exposures and personal behaviors to alter molecular or metabolic processes that increase the likelihood of disease development—or to mitigate such changes if the susceptibilities or the exposures are beneficial.
For example, smoking and tobacco use are risks for cancer—the risk of smokers getting lung cancer is ten to forty times that of nonsmokers. In some instances, a single gene abnormality will predominate over environmental influences. For example, familial hypercholesterolemia is a disorder resulting from a single abnormal gene that results in blood cholesterol levels two to four times above normal, depending on whether one or two alleles are inherited. Ischemic heart disease develops in middle or early adult life.
The usual modifiers of blood cholesterol levels, diet and physical activity, have little influence on cholesterol levels or disease development. The genetic risk overwhelms the environmental influences. However, the use of potent new drugs that decrease internal cholesterol synthesis in the body can lower blood cholesterol and the risk for heart disease. However, for the overwhelming majority of people, and for the majority of chronic diseases, alteration of personal and environmental exposures are the most important strategy.
Inherited diseases Genetic disorders are caused by errors in genetic information that produce diseases in the affected people. These errors may include: A change in the chromosome numbers, such as Down syndrome A defect in a single gene caused by mutation. A rearrangement of genetic information. Cystic fibrosis is an example of an inherited disease that is caused by a mutation on a gene. The faulty gene impairs the normal movement of sodium chloride in and out of cells, which causes the mucus-secreting organs to produce abnormally thick mucus.
The gene is recessive, meaning that a person must have two copies of the faulty gene for them to develop the disease. Cystic fibrosis affects the respiratory, digestive and reproductive systems, as well as the sweat glands. The mucus secreted is very thick and blocks passageways in the lungs and digestive tracts. This mucus causes problems with breathing and with the digestion and absorption of nutrients. Environmental diseases Environmental disease is a very broad category.
It includes avoidable and unavoidable conditions caused by external factors, such as sunlight, food, pollution, and lifestyle choices. The diseases of affluence are non-infectious diseases with environmental causes. Examples include: Many types of cardiovascular disease Chronic obstructive pulmonary disease caused by smoking tobacco Diabetes mellitus type 2 Lower back pain caused by too little exercise Malnutrition caused by too little food, or eating the wrong kinds of food (e. g. scurvy from lack of Vitamin C).
Skin cancer caused by radiation from the su A LOOK AHEAD The experience of high-income countries indicates that noncommunicable diseases can be prevented and managed with declines in death and disability. This “postindustrial” epidemiologic transition is based on the development and application of scientific information. Risk factors predict disease and their modification through public health and personal health measures can change disease patterns in individuals, groups, and populations. Technological development can assist this change through the development of vaccines, medicines, and foods.
However, personal behaviors and public health policies will always be important. These innovations can be transported throughout the world, but at a financial cost and with the need to assure cultural integrity. Cost, education, and cultural diversity will be barriers to be surmounted worldwide. Further investigation of risk will include appreciation of gene-environment interactions and exploration of new exposures. The improvement of health for all will depend on this progress.