Related concepts

The terms disease, disorder, medical condition are often used interchangeably. There is no agreed-upon universal distinction between these terms, though some people do make distinctions in particular contexts.
Medical usage sometimes distinguishes a disease, which has a known specific cause or causes (called its etiology), from a syndrome, which is a collection of signs or symptoms that occur together. However, many conditions have been identified, yet continue to be referred to as "syndromes." Furthermore, numerous conditions of unknown etiology are referred to as "diseases" in many contexts. Refractory diseases do not respond to therapy by overcoming the resistance to drugs.
Illness, although often used to mean disease, can also refer to a person's perception of their health, regardless of whether they in fact have a disease. A person without any disease may feel unhealthy and simply have the perception of having a disease. Another person may feel healthy with similar perceptions of perfectly good health. The individual's perception of good health may even persist with the medical diagnosis of having a disease; for example, such as dangerously high blood pressure, which may lead to a fatal heart attack or stroke.
Pathology is the study of diseases. The subject of systematic classification of diseases is referred to as nosology. Its cause is referred as its etiology. The broader body of knowledge about human diseases and their treatments is medicine. Many similar (and a few of the same) conditions or processes can affect non-human animals (wild or domestic). The study of diseases affecting animals is veterinary medicine.
Disease can be thought of as the presence of pathology, which can occur with or without subjective feelings of being unwell or social recognition of that state. Illness as the subjective state of "unwellness" can occur independently of, or in conjunction with, disease or sickness (with sickness the social classification of someone deemed diseased, which can also occur independently of the presence or absence of disease or illness (c.f. subjective medical conditions). Thus, someone with undetected high blood pressure who feels to be of good health would be diseased, but not ill or sick. Someone with a diagnosis of late-stage cancer would be diseased, probably feeling quite ill, and recognized by others as sick. A person incarcerated in a totalitarian psychiatric hospital for political purposes could arguably be then said to not be diseased, nor ill, but only classified as sick by the rulers of a society with which the person did not agree. Having had a bad day after a night of excess drinking, one might feel ill, but one would not be diseased, nor is it likely that a boss could be convinced of the sickness.

Causes nof diseases

Many different factors intrinsic or extrinsic to a person (or plant or animal) can cause disease. Examples of intrinsic factors are genetic defects or nutritional deficiencies. An environmental exposure, such as second-hand smoke is an example of an extrinsic factor. Many diseases result from a combination of intrinsic and extrinsic factors. For many diseases, no cause or set of causes has been identified.
There are many different factors that can cause disease. These can be broadly categorized into the following categories such as social, psychological, chemical, and biological. Some factors may fall into more than one category. Biochemical causes of disease can be considered as a spectrum where at one extreme disease is caused entirely by genetic factors (e.g. CAG repeats in the Huntingtin gene that causes Huntington's Disease) and at the other extreme is caused entirely by environmental factors. Environmental factors include toxic chemicals (e.g. acetaldehyde in cigarette smoke and dioxins released from the breakdown of Agent Orange) and infectious agents (e.g. smallpox virus and poliovirus). In between these extremes genes (e.g. NOD2/CARD15) and environmental factors (e.g. Gut microbiota) interact to cause disease, as seen for example in the inflammatory bowel disease Crohn's Disease .

Absence of the genetic or environmental factors in this case results in disease not being manifest. Koch's postulates can be used to determine whether a disease is caused by an infectious agent.
To determine whether a disease is caused by genetic factors, researchers study the pattern inheritance of the disease in families. This provides qualitative information about the disease (how it is inherited). A classic example of this method of research is inheritance of hemophilia in the British Royal Family. More recently this research has been used to identify the Apoliprotein E (ApoE) gene as a susceptibility gene for Alzheimer's Disease, though some forms of this gene - ApoE2 - are associated with a lower susceptibility. To determine to what extent a disease is caused by genetic factors (quantitative information), twin studies are used. Monozygotic twins are genetically identical and likely share a similar environment whereas dizygotic twins are genetically similar and likely share a similar environment. Thus by comparing the incidence of disease (termed concordance rate) in monozygotic twins with the incidence of disease in dizygotic twins, the extent to which genes contribute to disease can be determined. Candidate disease genes can be identified using a number of methods. One is to look for mutants of a model organism (e.g. the organisms Mus musculus,Drosophila melanogaster, Caenhorhabditis elegans,Brachydanio rerio and Xenopus tropicalis) that have a similar phenotype to the disease being studied. Another approach is to look for segregation of genes or genetic markers (e.g. single nucleotide polymorphism or expressed sequence tag


A large number of SNPs spaced throughout the genome have been identified recently in a large project called the HapMap project[1][2]). The usefulness of the HapMap project and SNP typing and their relevance to society was covered in the 27 October 2005 issue of the leading international science journal Nature (journal).
A large number of genes have been identified that contribute to human disease. These are available from the US National Library of Medicine, which has an impressive range of biological science resources available for free online. Amongst these resources is Online Mendelian Inheritance in Man - OMIM that provides a very, very comprehensive list of all known human gene mutations associated with, and likely contributing to, disease. Each article at OMIM is regularly updated to include the latest scientific research. Additionally, each article provides a detailed history of the research on a given disease gene, with links to the research articles. This resource is highly valuable and is used by the world's top science researchers. WHO defines heatlh as a, State of physically,mentally,socially,economically and spiritually well being not merely the absence of disease or infirmity.

Disease in human body

A disease is an abnormal condition of an organism that impairs bodily functions.[citation needed] In human beings, "disease" is often used more broadly to refer to any condition that causes discomfort, dysfunction, distress, social problems, and/or death to the person afflicted, or similar problems for those in contact with the person. 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.[citation needed]
While many diseases are biological processes with observable alterations of organ function or structure, others primarily involve alterations of behavior.
Classifying a condition as a disease is a social act of valuation, and may change the social status of the person with the condition (the patient). Some conditions (known as culture-bound syndromes) are only recognized as diseases within a particular culture. Sometimes the categorization of a condition as a disease is controversial within the culture.

Specialities

In addition to general dentistry, there are 9 recognized dental specialties in the US, Canada, and Australia. To become a specialist requires one to train in a residency or advanced graduate training program. Once residency is completed, the doctor is granted a certificate of specialty training. Many specialty programs have optional or required advanced degrees such as (MD/MBBS specific to Maxillofacial Surgery), MS, or PhD.
Dental Public Health (study of dental epidemiology and social health policies),
Endodontics (root canal therapy and study of diseases of the dental pulp),
Oral and Maxillofacial Pathology (study, diagnosis, and sometimes the treatment of oral and maxillofacial related diseases),
Oral and Maxillofacial Radiology (study and radiologic interpretation of oral and maxillofacial diseases),
Oral and Maxillofacial Surgery (extractions, facial surgery and implants),
Orthodontics and Dentofacial Orthopaedics (straightening of teeth and modification of midface and mandibular growth),
Pediatric Dentistry (i.e. dentistry for children, formerly known as "pedodontics"),
Periodontics (treatment of the periodontium, however most periodontists place implants),
Prosthodontics (dentures, bridges and the restoration of implants. Some prosthodontists further their training in "oral and maxillofacial prosthodontics--a discipline concerned with the replacement of missing facial structures--such as ears, eyes, nose, etc.)
Specialists in these fields are designated registrable (U.S. "Board Eligible") and warrant exclusive titles such as orthodontist, oral and maxillofacial surgeon, endodontist, pediatric dentist, periodontist, or prosthodontist upon satisfying certain local (U.S. "Board Certified"), (Australia/NZ: "FRACDS"), or (Canada: "FRCD(C)") registry requirements.
Two other post-graduate formal advanced education programs: General Practice Residency (advanced clinical and didactic training with intense hospital experience) and Advanced Education in General Dentistry (advanced training in clinical dentistry) recognized by the ADA do not lead to specialization.
Special category: Oral Biology - Research in Dental and Craniofacial Biology
Other dental education exists where no post-graduate formal university training is required: cosmetic dentistry, dental implant, temporo-mandibular joint therapy. These usually require the attendance of one or more continuing education courses that typically last for one to several days. There are restrictions on allowing these dentists to call themselves specialists in these fields. The specialist titles are registrable titles and controlled by the local dental licensing bodies.
Forensic odontology consists of the gathering and use of dental evidence in law. This may be performed by any dentist with experience or training in this field. The function of the forensic dentist is primarily documentation and verification of identity.
Geriatric dentistry or geriodontics is the delivery of dental care to older adults involving the diagnosis, prevention, and treatment of problems associated with normal ageing and age-related diseases as part of an interdisciplinary team with other health care professionals.
Veterinary dentistry, a speciality of veterinary medicine, is the field of dentistry applied to the care of animals [2][3].

General dentistry

Dentists can (and often do) further their training in one or more speciality areas (such as surgery, endodontics, orthodontics, etc.) Hence, there can be a great deal of variation between the level of skill in different disciplines from dentist to dentist, however all dentists must achieve a certain degree of skill in various disciplines in order to graduate from dental school and earn licensure. General practitioners, unlike specialists, have the luxury of choosing which services they will provide and which they will refer to specialists. It is important to note that most general practitioners perform restorative, prosthetic, routine endodontic therapy, routine periodontal therapy, and simple exodontia, as well as performing examinations. Others are comfortable treating more complex cases, as well as placing implants and extracting third molars...among many other procedures frequently referred to specialists. Contrary to popular belief, most dentists do not regularly clean teeth, and instead delegate this task to their support staff (e.g. dental hygienists).

Dentistry

Dentistry is the "evaluation, diagnosis, prevention and/or treatment (nonsurgical, surgical or related procedures) of diseases, disorders and/or conditions of the oral cavity, maxillofacial area and/or the adjacent and associated structures and their impact on the human body".[1] Those in the practice of dentistry are known as dentists. Other people aiding in oral health service include dental assistants, dental hygienists, dental technicians, and dental therapists.
A dentist is a healthcare professional qualified to practice dentistry after graduating with a degree of either Doctor of Dental Surgery (DDS), Doctor of Dental Medicine (DMD), Bachelor of Dentistry (BDent), Bachelor of Dental Science (BDSc), or Bachelor of Dental Surgery/Chirurgiae (BDS) or (BChD) or equivalent. In most western countries, to become a qualified dentist one must usually complete at least 4 years of postgraduate study[citation needed]. Generally, 2 years of clinical experience working with patients in an educational setting are required.[citation needed

Health systems in Asia

Israel,[37] South Korea, Seychelles and Taiwan have universal health care. Thailand[38] plans to.[39] Health care in India is guaranteed to "improve" for all under the constitution, although the reality does not live up to the vague wording of the article. In Sri Lanka, drugs are provided by a government owned drug manufacturer called the State Pharmaceuticals Corporation of Sri Lanka. In the Philippines, the Department of Health (Philippines) organises public health for the country, and was established at the initiative of the American governors, before independence. Saudi Arabia has a publicly funded health system, although its levels are lower than the regional average.

National Health Service(united kingdom)

The NHS is the world's largest, centralised health service, and the world's third largest employer after the Chinese army and the Indian railways. It was created in the aftermath of World War II, by Clement Attlee's Labour government, based on the proposals of the Beveridge Report, prepared in 1942.[18] The structure of the NHS in England and Wales was established by the National Health Service Act 1946 (1946 Act). The current Labour government has invested billions of new money in the NHS. However, Tony Blair's policy, whilst leaving services free at point of use, was to encourage outsourcing of medical services and support to the private sector. Under the Private Finance Initiative, an increasing number of hospitals have been built (or rebuilt) by private sector consortia; hospitals may have both medical services (such as "surgicentres"),[19] and non-medical services (such as catering) provided under long-term contracts by the private sector. These are more expensive than if the new build was simply funded from the public purse. A study by a consultancy company which works for the Department of Health shows that every £200 million spent on privately financed hospitals will result in the loss of 1000 doctors and nurses. The first PFI hospitals contain some 28 per cent fewer beds than the ones they replaced.[20] Even so there is for the first time complete political consensus on the importance of free public health ca

World Health Organization

The World Health Organization (WHO) is a specialised United Nations agency which acts as a coordinator and researcher for public health around the world. Established on 7 April 1948, and headquartered in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health Organization, which had been an agency of the League of Nations. The WHO's constitution states that its mission "is the attainment by all peoples of the highest possible level of health." Its major task is to combat disease, especially key infectious diseases, and to promote the general health of the peoples of the world. Examples of its work include years of fighting smallpox. In 1979 the WHO declared that the disease had been eradicated - the first disease in history to be completely eliminated by deliberate human design. The WHO is nearing success in developing vaccines against malaria and schistosomiasis and aims to eradicate polio within the next few years. The organization has already endorsed the world's first official HIV/AIDS Toolkit for Zimbabwe from October 3, 2006, making it an international standard.[14]
The WHO is financed by contributions from member states and from donors. In recent years the WHO's work has involved more collaboration, currently around 80 such partnerships, with NGOs and the pharmaceutical industry, as well as with foundations such as the Bill and Melinda Gates Foundation and the Rockefeller Foundation. Voluntary contributions to the WHO from national and local governments, foundations and NGOs, other UN organizations, and the private sector (including pharmaceutical companies), now exceed that of assessed contributions (dues) from its 193 member nations.[15]

Health care systems

Purely private enterprise health care systems are comparatively rare. Where they exist, it is usually for a comparatively well-off subpopulation in a poorer country with a poorer standard of health care–for instance, private clinics for a small, wealthy expatriate population in an otherwise poor country. But there are countries with a majority-private health care system with residual public service (see Medicare, Medicaid). The other major models are public insurance systems. A Social security health care model is where workers and their families are insured by the State. A Publicly funded health care model is where the residents of the country are insured by the State. Within this branch is Single-payer health care, which describes a type of financing system in which a single entity, typically a government run organisation, acts as the administrator (or "payer") to collect all health care fees, and pay out all health care costs.[10] Some advocates of universal health care assert that single-payer systems save money that could be used directly towards health care by reducing administrative waste.[10] In practice this means that the government collects taxes from the public, businesses, etc., creates an entity to administer the supply of health care and then pays health care professionals. Harry Wachtel estimate a single payer universal healthcare system will actually save money through reduced bureaucratic administration costs.[11] Social health insurance is where the whole population or most of the population is a member of a sickness insurance company. Most health services are provided by private enterprises which act as contractors, billing the government for patient care.[12] In almost every country with a government health care system a parallel private system is allowed to operate. This is sometimes referred to as two-tier health care. The scale, extent, and funding of these private systems is very variable.
A traditional view is that improvements in health result from advancements in medical science. The medical model of health focuses on the eradication of illness through diagnosis and effective treatment. In contrast, the social model of health places emphasis on changes that can be made in society and in people's own lifestyles to make the population healthier. It defines illness from the point of view of the individual's functioning within their society rather than by monitoring for changes in biological or physiological signs.[13]

Health care industry

The health care industry is considered an industry or profession which includes peoples exercise of skill or judgment or the providing of a service related to the preservation or improvement of the health of individuals or the treatment or care of individuals who are injured, sick, disabled, or infirm. The delivery of modern health care depends on an expanding group of trained professionals coming together as an interdisciplinary team.[4][5]
The health care industry is one of the world's largest and fastest-growing industries.[6] Consuming over 10 percent of gross domestic product of most developed nations, health care can form an enormous part of a country's economy. In 2003, health care costs paid to hospitals, physicians, nursing homes, diagnostic laboratories, pharmacies, medical device manufacturers and other components of the health care system, consumed 15.3 percent[7] of the GDP of the United States, the largest of any country in the world. For the United States, the health share of gross domestic product (GDP) is expected to hold steady in 2006 before resuming its historical upward trend, reaching 19.6 percent of GDP by 2016.[8] In 2001, for the OECD countries the average was 8.4 percent[9] with the United States (13.9%), Switzerland (10.9%), and Germany (10.7%) being the top three.

introdution about health care

Health care, or healthcare, is the prevention, treatment, and management of illness and the preservation of mental and physical well being through the services offered by the medical, nursing, and allied health professions. According to the World Health Organization, health care embraces all the goods and services designed to promote health, including “preventive, curative and palliative interventions, whether directed to individuals or to populations”.[1] The organised provision of such services may constitute a health care system. This can include a specific governmental organisation such as, in the UK, the National Health Service or a cooperation across the National Health Service and Social Services as in Shared Care. Before the term "health care" became popular, English-speakers referred to medicine or to the health sector and spoke of the treatment and prevention of illness and disease.
In most developed countries and many developing countries health care is provided to everyone regardless of their ability to pay. The National Health Service in the United Kingdom was the world's first universal health care system provided by government. It was established in 1948 by Clement Atlee's Labour government. Alternatively, compulsory government funded health insurance with nominal fees can be provided, as with Italy, which, according to the World Health Organisation, has the second-best health system in the world.[2] Other examples are Medicare in Australia, established in the 1970s by the Labor government, and by the same name Medicare in Canada, established between 1966 and 1984. Universal health care contrasts to the systems like health care in the United States or South Africa, though South Africa is one of the many countries attempting health care reform.[3]