A disease is an abnormal condition of an organism that impairs bodily functions,^[1] associated with specific symptoms and signs. A symptom' (from Greek σύμπτωμα, "accident misfortune that which befalls" from συμπίπτω, "I befall" from A Sign is an indication of some fact or quality and a medical sign is an objective indication of some medical fact or quality that is detected by a Physician ^[2][3]

In human beings,"disease" is often used more broadly to refer to any condition that causes extreme pain, dysfunction, distress, social problems, and/or death to the person afflicted, or similar problems for those in contact with the person. Pain, in the sense of physical pain, is a typical sensory experience that may be described as the unpleasant awareness of a noxious stimulus or bodily harm Social issues are matters which directly or indirectly affect many or all members of a Society and are considered to be problems controversies related to Moral values Death is the termination of the biological functions that define living Organisms It refers both to a specific In this broader sense, it sometimes includes injuries, disabilities, disorders, syndromes, infections, isolated symptoms, deviant behaviors, and atypical variations of structure and function, while in other contexts and for other purposes these may be considered distinguishable categories. Injury or bodily injury is Damage or Harm caused to the Structure or function of the Body caused by an outside agent or In medicine a disorder is a functional abnormality or disturbance In Medicine and Psychology, the term syndrome refers to the association of several clinically recognizable features signs (observed by a physician An infection is the detrimental Colonization of a host Organism by a foreign Species. A symptom' (from Greek σύμπτωμα, "accident misfortune that which befalls" from συμπίπτω, "I befall" from Behavior or behaviour (see spelling differences) refers to the actions or Reactions of an object or Organism, usually Human variability, or human variation, is the range of possible values for any measurable characteristic physical or mental of human beings

Transmission of disease

Main article: Transmission (medicine)

Some diseases such as influenza are contagious and infectious. In Medicine, transmission is the passing of a Disease from an infected individual or group to a previously uninfected individual or group An infectious disease is a clinically evident Disease resulting from the presence of Pathogenic microbial agents including Pathogenic viruses Pathogenic Infectious diseases can be transmitted by any of a variety of mechanisms, including inhalation of aerosols produced by coughs and sneezes, by hand to mouth contact with infectious material on surfaces, by bites of insects or other carriers of the disease, and from contaminated water or food (often via faecal contamination), etc. Technically an aerosol is a suspension of fine solid particles or liquid droplets in a gas In Medicine, a cough ( Latin: tussis) is a sudden and often repetitively occurring defence Reflex which helps to clear the large breathing passages A sneeze (or sternutation) is a semi-autonomous Convulsive expulsion of Air from the Lungs, most commonly caused by foreign particles Feces, faeces, or fæces (see spelling differences) is a waste product from an animal's digestive tract expelled through the Anus In addition, there are sexually transmitted diseases. A sexually transmitted disease ( STD) or venereal disease ( VD) is an illness that has a significant probability of transmission between Humans In some cases, micro-organisms that are not readily spread from person to person play a role, while other diseases can be prevented or ameliorated with appropriate nutrition or other lifestyle changes. A microorganism (also spelled micro organism or micro-organism and also called a microbe) is an Organism that is Microscopic (usually Nutrition (also called nourishment or aliment) is the provision to cells and Organisms of the materials necessary (in the form of food to support Some diseases such as cancer, heart disease and mental disorders are, in most cases, not considered to be caused by infection, although there are important exceptions. Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled Heart disease is an Umbrella term for a variety for different diseases affecting the Heart. Many diseases (including some cancers, heart disease and mental disorders) have a partially or completely genetic basis (see Genetic disorder) and may thus be transmitted from one generation to another. A genetic disorder is a condition caused by abnormalities in Genes or Chromosomes While some diseases such as Cancer, are due to genetic abnormalities acquired

Social significance of disease

Living with disease can be very difficult. The identification of a condition as a disease, rather than as simply a variation of human structure or function, can have significant social or economic implications. The controversial recognitions as diseases of post-traumatic stress disorder, also known as "Soldier's heart," "shell shock," and "combat fatigue;" repetitive motion injury or repetitive stress injury (RSI); and Gulf War syndrome has had a number of positive and negative effects on the financial and other responsibilities of governments, corporations and institutions towards individuals, as well as on the individuals themselves. Post traumatic stress disorder It is a severe and ongoing emotional reaction to A repetitive strain injury (RSI also called cumulative trauma disorder ( CTD) occupational overuse syndrome, or work related upper limb disorder A repetitive strain injury (RSI also called cumulative trauma disorder ( CTD) occupational overuse syndrome, or work related upper limb disorder Gulf War syndrome (GWS or Gulf War illness (GWI is an Illness reported by combat Veterans of the 1991 Persian Gulf War typified by Symptoms The social implication of viewing aging as a disease could be profound, though this classification is not yet widespread. Senescence refers to the biological processes of a living Organism approaching an advanced age (i

A condition may be considered to be a disease in some cultures or eras but not in others. Oppositional-defiant disorder, attention-deficit hyperactivity disorder, and, increasingly, obesity, are conditions considered to be diseases in the United States and Canada today, but were not so-considered decades ago and are not so-considered in some other countries. Oppositional defiant disorder is a psychiatric category listed in the Diagnostic and Statistical Manual of Mental Disorders where it is described as an ongoing pattern of Attention-Deficit Hyperactivity Disorder (ADHD is a neurobehavioral developmental disorder affecting about 3-5% of the world's population Obesity is a condition in which excess Body fat has accumulated to such an extent that health may be negatively affected Lepers were a group of afflicted individuals who were historically shunned and the term "leper" still evokes social stigma. Leprosy (from the Greek lepi (λέπι meaning scales on a fish or Hansen's disease, is a chronic disease caused by the bacterium Fear of disease can still be a widespread social phenomena, though not all diseases evoke extreme social stigma.

Sickness confers the social legitimization of certain benefits, such as illness benefits, work avoidance, and being looked after by others. In return, there is an obligation on the sick person to seek treatment and work to become well once more. As a comparison, consider pregnancy, which is not a state interpreted as disease or sickness by the individual. Pregnancy ( Latin graviditas) is the carrying of one or more offspring known as a Fetus or Embryo, inside the Uterus of a Female On the other hand, it is considered by the medical community as a condition requiring medical care and by society at large as a condition requiring one's staying at home from work.

Global burden of disease

Main article: Global burden of disease

This chart, compiled in 2002 from the global burden of disease study performed by the World Health Organization shows an overview of the impact of various classifications of disease, segregated by regions with low and high mortality:

References

External links

• Health Topics, MedlinePlus descriptions of most diseases, with access to current research articles. The global burden of disease ( GBD) is a comprehensive regional and global assessment of mortality and Disability from 107 diseases and injuries and ten The global burden of disease ( GBD) is a comprehensive regional and global assessment of mortality and Disability from 107 diseases and injuries and ten Dorland's is the brand name of a family of medical reference works (including dictionaries, spellers word books and spell-check software) in various media (including MedlinePlus, with the MedlinePlus Medical Encyclopedia, is a website network containing Health information from the world's largest medical Library
• OMIM The best web resource for information on genes that cause disease at Online Mendelian Inheritance in Man
• CTD The Comparative Toxicogenomics Database is a scientific resource connecting chemicals, genes, and human diseases. The Mendelian Inheritance in Man project is a Database that catalogues all the known Diseases with a genetic component, and—when possible—links them The Comparative Toxicogenomics Database (CTD is a public website and research tool that curates scientific data describing relationships between chemicals genes and human diseases
• NLM The most comprehensive database of top quality science information on the web at US National Library of Medicine
• Health Topics A-Z, fact sheets about many common diseases at Center for Disease Control
• GluvSnap.com, Latest disease and medical news
• The Merck manual containing detailed description of most diseases
• Dynamic Differential Diagnosis