Medicine is a branch of health science concerned with
restoring and maintaining health. Broadly, it is the practical science of preventing and curing diseases. However,
medicine often refers more specifically to matters dealt with by physicians and surgeons.
Medicine is both an area of knowledge (a science), and the application of that
knowledge (by the medical profession and other health professionals such as nurses). The various specialized branches of the
science of medicine correspond to equally specialized medical professions dealing with particular organs or diseases. The
science of medicine is the knowledge of body systems and diseases, while the profession of medicine refers to the social structure of the group of people formally
trained to apply that knowledge to treat disease.
There are traditional and schools of healing which are usually not considered to be part of (Western) medicine in a strict
sense (see health science for an overview). The most highly developed
systems of medicine outside of the Western or Hippocratic tradition are the
Ayurvedic school (of India) and traditional Chinese
medicine. The remainder of this article focuses on modern (Western) medicine.
History of medicine
See the main articles History of medicine and Timeline of medicine and
medical technology
Medicine as it is practiced now is rooted in various traditions, but developed mainly in the late 18th and early 19th century in Germany (Rudolf Virchow) and
France (Jean-Martin
Charcot and others). The new, "scientific" medicine replaced more traditional views based on the "Four humours". The development of clinical medicine shifted to the United Kingdom and the USA during the early 1900s (Sir William Osler, Harvey Cushing).
Evidence-based medicine is the recent movement to
link the practice and the science of medicine more closely through the use of the scientific method and modern information
science.
Genomics is already having a large influence on medical practice, as most
monogenic genetic
disorders have now been linked to causative genes, and molecular biological techniques are influencing medical
decision-making.
Practice of medicine
The medical encounter or patient-doctor relationship is an important part of what medicine is about (there are other relationships between
health professionals and patients that are equally important, e.g. nurse - patient). A person with a health problem or concern
sees a doctor for help. The practice of medicine combines both science and art. Science and technology are the evidence base
for many clinical problems for the general population at large. The art of medicine is the application of this medical knowledge
in combination with intuition and clinical judgment to determine the proper diagnoses and treatment plan for this unique patient
and to treat the patient accordingly.
The doctor needs to:
- develop a relationship with the patient
- gather data (medical history and physical examination
combined with laboratory or imaging studies)
- analyze and synthesize that data (assessment and/or differential diagnosis), and then
- develop a treatment plan (more testing, therapy, watchful observation, referral and follow-up)
- treat the patient accordingly.
The medical encounter is documented in a medical record. One method
that is used is called the problem-oriented medical record (POMR), which includes a problem list of diagnoses and a "SOAP"
method of documentation for each visit:
- S - Subjective, the medical history of the problem from the point-of-view of the patient.
- O - Objective, the physical examination and any laboratory or imaging studies.
- A - Assessment, is the medical decision-making process including the differential diagnoses and most probable
diagnoses.
- P - Plan, the way resolve the problem and monitor progress
Medical systems
Medicine is practiced within the medical system of a particular culture or government. Leaving aside tribal cultures, the most
significant divide in developed countries is that between universal health care and the market based health care (such as practiced in the US).
Patient-doctor relationship
The doctor-patient relationship and interaction is a central process in the practice of medicine. There are many perspectives
from which to understand and describe it.
An idealized physician's perspective, such as is taught in medical school, sees the core aspects of the process as the
physician learning from the patient his symptoms, concerns and values; in response the physician examines the patient, interprets
the symptoms, and formulates a diagnosis to explain the symptoms and their cause to the patient and to propose a treatment. In
more detail, the patient presents a set of complaints or concerns about his health to the doctor, who then obtains further
information about the patient's symptoms, previous state of health, living conditions, and so forth, and then formulates a
diagnosis and enlists the patient's agreement to a treatment plan. Importantly, during this process the doctor educates the
patient about the causes, progression, outcomes, and possible treatments of his ailments, as well as often providing advice for
maintaining health. This teaching relationship is the basis of calling the physician doctor, which originally meant "teacher" in Latin. The patient-doctor relationship is additionally complicated by
the patient's suffering (patient comes from the Latin patiens, "suffering") and limited ability to relieve it on his own.
The doctor's expertise comes from his knowledge about, or experience with, other people who have suffered similar symptoms, and
his presumed ability to relieve it with medicines or other therapies about which the patient may initially have little
knowledge.
The doctor-patient relationship can be analyzed from the perspective of ethical concerns, in terms of how well the goals of non-maleficence, beneficence, autonomy, and justice are
achieved. Many other values and ethical issues can be added to these. In different societies, periods, and cultures, different
values may be assigned different priorities. For example, in the last 30 years medical care in the Western World has increasingly
emphasized patient autonomy in decision making.
The relationship and process can also be analyzed in terms of social power relationships (e.g., by Michel Foucault), or economic transactions. Physicians have been accorded
gradually higher status and respect over the last century, and they have been entrusted with control of access to prescription
medicines as a public health measure. This represents a concentration of power and carries both advantages and disadvantages to
particular kinds of patients with particular kinds of conditions. A further twist has occurred in the last 25 years as costs of
medical care have risen, and a third party (an insurance company or government
agency) now often insists upon a share of decision-making power for a variety of reasons, reducing freedom of choice of both
doctors and patients in many ways.
The quality of the patient-doctor relationship is important to both parties. The better the relationship in terms of mutual
respect, knowledge, trust, shared values and perspectives about disease and life, and time available, the better will be the
amount and quality of information about the patient's disease transferred in both directions, enhancing accuracy of diagnosis and
increasing the patient's knowledge about the disease.
In some settings, e.g. the hospital ward, the patient-doctor relationship is much more complex, and many other people are
involved when somebody is ill: relatives, neighbors, rescue specialists, nurses, technical personnel, social workers and
others.
Clinical skills
A complete medical evaluation includes a medical history, a physical examination, appropriate laboratory or imaging studies,
analysis of data and medical decision making to obtain diagnoses, and treatment plan.
The components of the medical history are:
- Chief complaint (CC) - the reason for the current medical visit.
- History of present illness (HPI) - the chronological order of events of symptoms. A mnemonic PQRST is sometimes helpful in obtaining the history:
- Provocative-palliative factors - what makes a symptom worse or better.
- Quality - description of the symptom
- Region - which part of the body is affected
- Severity - what is the intensity of the symptom; using a scale of 0-10 (10 worst)
- Timing - what is the course of the symptom
- Current activity - occupation, hobbies, what the patient actually does.
- Medications - what drugs including OTCs, and home remedies. Drug allergies are important
- Past medical history (PMH) - other medical diagnoses, past hospitalizations and operations, injuries, past infectious diseases
and/or vaccinations
- Review of systems (ROS) - an outline of additional symptoms to ask which may be missed on HPI, generally following the body's
main organ systems (heart, lungs, digestive tract, urinary tract, etc.)
- Social history (SH) - birthplace, residences, marital history, social and economic status, habits including diet, drugs, tobacco, alcohol
- Family history (FH) - listing of diseases in the family that may impact the patient. A family tree is sometimes used.
The physical examination is the examination of the
patient looking for signs of disease. The doctor uses his senses of sight, hearing, touch, and sometimes smell (taste has been
replaced by modern lab tests). Four chief methods are used: inspection, palpation, percussion, and auscultation; smelling may be
useful (e.g. infection, uremia, diabetic ketoacidosis).
- Vital signs include height, weight, body temperature, blood pressure, pulse,
respiration rate, hemoglobin oxygen saturation
- General appearance of the patient
- Skin
- Head, eye, ear, nose, and throat (HEENT)
- Cardiovascular - heart and blood vessels
- Respiratory - lungs
- Abdomen and rectosigmoid
- Genitalia
- Spine and extremities - musculoskeletal
- Neuropsychiatric
Laboratory and imaging studies results, if any.
Medical decision making (MDM) process involves the analysis and synthesis of all the above data to come with a list of
possible diagnoses (the differential diagnoses) and
what needs to be done to come up with a final diagnosis which would explain the patient's problem.
Treatment plan may include ordering additional labs and studies, starting therapy, referring to a specialist, or watchful
observation. Follow-up may be needed.
This process is used by primary care providers and well as specialists. It may take only a few minutes if the problem is
simple and straightforward. Or it may take weeks for a patient who has been hospitalized with multiple system problems involving
several specialists.
On subsequent visits, the process may be repeated in an abbreviated manner to obtain any new history, symptoms, physical
findings, and lab or imaging results or specialist consultations.
Settings where medical care is delivered
See also clinic, hospital, and
hospice
Medicine is a diverse field and the provision of medical care is therefore provided in a variety of locations.
Primary care medical services are provided by physicians or other health
professionals who has first contact with a patient seeking medical treatment or care. These occur in physician's office, clinics, nursing homes, schools, home visits and other places close to patients.
About 90% of medical visits can be treated by the primary care provider. These include treatment of acute and chronic illnesses,
preventive care and health education for all ages and both sex.
Secondary care medical services are provided by medical specialists in their offices or clinics or at local community
hospitals for a patient referred by a primary care provider who first diagnosed or treated the patient. Referrals are made for
those patients who required the expertise or procedures performed by specialists. These include both ambulatory care and inpatient
services, emergency rooms, intensive care medicine, surgery services,
physical therapy, labor and delivery, endoscopy units, diagnostic laboratory and medical
imaging services, hospice centers, etc. Some primary care providers may also take
care of hospitalized patients and deliver babies in a secondary care setting.
Tertiary care medical services are provided by specialist hospitals or regional centers equipped with diagnostic and treatment
facilities not generally available at local hospitals. These include trauma
centers, burn treatment centers, advanced neonatology unit services, organ transplants, high-risk pregnancy, radiation oncology, etc.
Modern medical care also depends on information - still delivered in many health care settings on paper records, but
increasingly nowadays by electronic means.
Branches of medicine
The delivery of modern health care depends, not just on medical practitioners, but on an expanding group of highly trained
professionals coming together as an interdisciplinary team. A full list is given on the health profession page. Some examples include: nurses, laboratory
scientists, pharmacists, physiotherapists, speech therapists, occupational therapists, dietitians and bioengineers.
The scope and sciences underpinning human medicine overlap many other fields. Dentistry and psychology, while separate
disciplines from medicine, are sometimes also considered medical fields. Physician assistants, nurse
practitioners and midwives treat patients and prescribe medication in many
legal jurisdictions. Veterinary medicine applies similar
techniques to the care of animals.
Medical doctors have many specializations and subspecializations which are listed below.
Basic sciences
- Anatomy is the study of the physical structure of organisms. In contrast
to macroscopic or gross anatomy, cytology and histology are concerned with microscopic
structures.
- Biochemistry is the study of the chemistry taking place in
living organisms, especially the structure and function of their chemical components.
- Biostatistics is the application of statistics to biological
fields in the broadest sense. A knowledge of biostatistics is essential in the planning, evaluation, and interpretation of
medical research. It is also fundamental to epidemiology and evidence-based
medicine.
- Cytology is the microscopic study of individual cells.
- Embryology is the study of the early development of organisms.
- Epidemiology is the study of the demographics of disease
processes, and includes, but is not limited to, the study of epidemics.
- Genetics is the study of genes, and their role in biological inheritance.
- Histology is the study of the structures of biological tissues by light microscopy, electron microscopy and
histochemistry.
- Immunology is the study of the immune system, which includes the innate and adaptive immune system in human, for example.
- Microbiology is the study of microorganisms, including protozoa,
bacteria, fungi, and viruses.
- Neuroscience is a comprehensive term for those disciplines of
science that are related to the study of the nervous system. A main focus of neuroscience is the biology and physiology of the
human brain.
- Nutrition is the study of the relationship of food and drink to health
and disease, especially in determining an optimal diet. Medical nutrition therapy is done by dietitians and is prescribed for
diabetes, cardiovascular diseases, weight and eating disorders, allergies, malnutrition and neoplastic diseases.
- Pathology is the study of disease - the causes, course, progression
and resolution thereof.
- Pharmacology is the study of drugs and their actions.
- Physiology is the study of the normal functioning of the body and
the underlying regulatory mechanisms.
- Toxicology is the study of hazardous effects of drugs and poisons.
Diagnostic specialties
- Clinical laboratory sciences are the clinical diagnostic services which apply laboratory
techniques to diagnosis and management of patients. In the United States these
services are supervised by a Pathologist. The personnel that work in these medical laboratory departments are technically trained staff, each of whom usually hold a medical technology degree, who actually perform the tests, assays, and
procedures needed for providing the specific services.
- Radiology is concerned with imaging of the human body, e.g. by
x-rays, x-ray computed
tomography, ultrasonography, and nuclear magnetic resonance tomography.
- Interventional radiology is concerned
with using imaging of the human body, usually from CT, ultrasound, or fluoroscopy, to do biopsies, place certain tubes, and perform
intravascular procedures.
- Nuclear Medicine uses radioactive substances for in vivo and in vitro diagnosis using either imaging of the location of radioactive substances
placed into a patient, or using in vitro diagnostic tests utilizing radioactive substances.
Clinical disciplines
- Anesthesiology (AE), Anaesthesia (BE), is the clinical
discipline concerned with providing anesthesia. Pain medicine is often practiced by specialised anesthesiologists.
- Dermatology is concerned with the skin and its diseases.
- Emergency medicine is concerned with the diagnosis
and treatment of acute or life-threatening conditions, including trauma, surgical, medical, pediatric, and psychiatric
emergencies.
- General practice or family medicine or primary
care is, in many countries, the first port-of-call for patients with non-emergency medical problems. Family doctors are
usually able to treat over 90% of all complaints without referring to specialists.
- Geriatrics is concerned with medical care of the elderly.
- Hospital medicine is the general medical care of
hospitalized patients. Doctors whose primary professional focus is hospital medicine are called hospitalist.
- Intensive care medicine is concerned with
the therapy of patients with serious and life-threatening disease or injury. Intensive care medicine employs invasive diagnostic
techniques and (temporary) replacement of organ functions by technical means.
- Internal medicine is concerned with diseases of inner
organs and systemic dieseases of adults, i.e. such that affect the body as a whole. There are several subdisciplines of internal
medicine:
- Cardiology is concerned with the heart and cardiovascular system and
their diseases.
- Gastroenterology is concerned with the organs of
digestion.
- Endocrinology is concerned with the endocrine system, i.e.
endocrine glands and hormones.
- Hematology (or haematology) is concerned with the blood and
its diseases.
- Infectious diseases is concerned with the study,
diagnosis and treatment of diseases caused by biological agents.
- Nephrology is concerned with diseases of the kidneys.
- Oncology is devoted to the study, diagnosis and treatment of cancer and other malignant diseases.
- Pulmonology (or chest medicine, respiratory medicine
or lung medicine) is concerned with diseases of the lungs and the respiratory system.
- Rheumatology is devoted to the diagnosis and treatment of
inflammatory diseases of the joints and other organ systems.
- Neurology is concerned with the diagnosis and treatment of nervous system diseases.
- Obstetrics and gynecology are concerned respectively with childbirth and the female reproductive and associated organs.
Reproductive
medicine and fertility
medicine is generally practiced by gynecological specialists.
- Palliative care is a relatively modern branch of clinical
medicine that deals with pain and symptom relief and emotional support in patients with terminal disease (cancer, heart failure).
- Pediatrics (or paediatrics) is devoted to the care of
children, and adolescents. Like internal medicine, there are many pediatric supspecialities for specific age ranges, organ
systems, disease classes and sites of care delivery. Most subspecialities of adult medicine have a pediatric equivalent such as
pediatric
cardiology, pediatric endocrinology, pediatric
gastroenterology, pediatric hematology, and pediatric oncology.
- Physical medicine and
rehabilitation (or physiatry) is concerned with functional improvement after injury, illness, or congenital
abnormality.
- Preventive medicine
- Psychiatry is a branch of medicine that studies and treats mental
disorders. Related non-medical fields are psychotherapy and clinical psychology. There are several subdisciplines of Psychiatry:
- Child & adolescent psychiatry focuses on the care of children and adolescents
with mental/emotional/learning problems (i.e., ADHD, Autism, family conflicts).
- Geriatric
psychiatry focuses on the care of elderly people with mental illnesses (i.e., dementias, post stroke cognitive changes,
depression).
- Addiction
psychiatry focuses on substance abuse and its treatment.
- Forensic psychiatry focuses on the interface of
psychiatry and the Law.
- Radiation therapy is concerned with the therapeutic
use of ionizing radiation and high energy elementary particle beams in patient treatment.
- Radiology has both diagnostic and therapeutic branches. Diagnostic
radiology utilizes X-rays, CT scans, ultrasound and MRI to diagnose disease. Interventional radiology uses these imaging techniques to guide
treatments for certain diseases.
- Surgical specialties - there are many medical disciplines that employ operative treatment. Some of these are highly
specialized and are often not considered subdisciplines of surgery, although their naming might suggest so.
- General surgery is traditionally defined as the specialty
of surgery of the skin, endocrine glands, and abdomen (and, sometimes, the mammary glands). In some countries, it is still deemed
a pre-requisite training prior to progression to training in certain sub-specialties, but lately has evolved into its own
sub-specialty.
- Cardiovascular surgery is the surgical
specialty that is concerned with the heart and major blood vessels of the chest.
- Neurosurgery is concerned with the operative treatment of
diseases of the nervous system.
- Maxillofacial surgery (technically a
subspeciality of dentistry)
- Ophthalmology deals with the diseases of the eye and their
treatment.
- Orthopedic surgery consists on surgery of the
locomotor system.
- Otolaryngology (or otorhinolaryngology or
ENT/ear-nose-throat) is concerned with treatment of ear, nose and throat disorders. The term head and neck surgery
defines a closely related specialty which is concerned mainly with the surgical management of cancer of the same anatomical structures.
- Pediatric surgery treats a wide variety of thoracic and abdominal (and sometimes urologic) diseases of childhood.
- Plastic surgery includes aesthetic surgery (operations
that are done for other than medical purposes) as well as reconstructive surgery (operations to restore function and/or
appearance after traumatic or operative mutilation).
- Surgical oncology is concerned with curative and
palliative surgical approaches to cancer treatment
- Urology focuses on the urinary tracts of males and females, and on the
male reproductive system. It is often practiced together with andrology ("men's
health").
- Vascular surgery is surgery of "peripheral" blood
vessels, i.e. those outside of the chest (usually operated on by cardiovascular surgeons) and of the central nervous system (treated by neurosurgery).
Interdisciplinary fields
Interdisciplinary sub-specialties of medicine are:
- Aerospace medicine deals with medical problems
related to flying and space travel.
- Bioethics is a field of study which concerns the relationship between
biology, science, medicine and ethics, philosophy and theology.
- Clinical pharmacology is concerned with how
systems of therapeutics interact with patients.
- Conservation medicine studies the relationship
between human and animal health, and environmental conditions. Also known as ecological medicine, environmental medicine, or
medical geology.
- Diving medicine (or hyperbaric medicine) is the prevention and treatment of diving-related problems.
- Forensic medicine deals with medical questions in
legal context, such as determination of the time and cause of death.
- Medical humanities includes the humanities (literature, philosophy, ethics, history and religion), social science (anthropology, cultural studies, psychology, sociology), and the arts (literature, theater, film, and visual
arts) and their application to medical education and practice.
- Medical informatics and medical computer science are relatively recent fields
that deal with the application of computers and information technology to medicine.
- Nosology is the classification of diseases for various purposes.
- Sports medicine deals with the treatment and preventive
care of athletics, amateur and professional. The team includes specialty physicians and surgeons, athletic trainers, physical
therapists, coaches, other personnel, and, of course, the athlete.
Medical education
See also the main article, Medical doctor (BE) or Physician (AE)
Medical training involves several years of university study followed by several more years of residential practice at a
hospital. Entry to a medical degree in some countries (such as the United
States) requires the completion of another degree first, while in other countries (such as the United Kingdom, Australia and New Zealand) medical training can be commenced as an undergraduate degree immediately
after secondary education.
The name of the medical degree gained at the end varies: some
countries (e.g. the US) call it "Doctor of Medicine" (abbreviated 'M.D.'), while other countries (mostly following the British
Oxbridge system) call it "Medicinæ Baccalaureus & Baccalaureus
Chirurgiæ" (Latin for "Bachelor
of Medicine/Bachelor of Surgery", Old English: "Chirurgie"); this
is technically a double degree, frequently abbreviated 'MB BChir', 'MB ChB', 'MB BS' (or variations thereof), dependent on the
medical school. In either case, graduates of a medical degree may call themselves physician. In the US and some other countries
there is a parallel system of medicine called "osteopathy" which awards the
degree D.O. (doctor of osteopathy). In many countries, a doctorate of medicine does not
require original research as does, in distinction, a Ph.D..
Once graduated from medical school most physicians begin their residency/house post training, where skills in a speciality of
medicine are learned, supervised by more experienced doctors. The first year of residency is known as the "intern" year (USA) or "junior/pre-registration house officer" year (UK). The duration of residency training
depends on the speciality.
A medical graduate can then enter general practice and become a
general practitioner (or primary care internist in the USA); training
for these is generally shorter, while specialist training is typically longer.
Legal restrictions
In most countries, it is a legal requirement for medical doctors to be licensed or registered. In general, this entails a
medical degree from a university and accreditation by a medical board or an equivalent national organization, which may ask the applicant to pass exams. This
restricts the considerable legal authority of the medical profession to doctors that are trained and qualified by national
standards. It is also intended as an assurance to patients and as a safeguard against charlatans that practice inadequate medicine for personal gain. While the laws generally require medical doctors
to be trained in "evidence based", Western, or Hippocratic Medicine, they are
not intended to discourage different paradigms of health and healing, such as alternative medicine or faith healing.
Criticism
Criticism against medicine has a long history. In the Middle Ages, it was
not considered a profession suitable for Christians, as disease was considered Godsent, and interfering with the process a form
of blasphemy. Barber-surgeons generally had a bad reputation that was not to
improve until the development of academic surgery as a specialism of medicine, rather than an accessory field.
Through the course of the twentieth century, doctors naturally focused increasingly on the technology that was enabling them
to make dramatic improvements in patients' health. This resulted in criticism for the loss of compassion and mechanistic,
detached treatment. This issue started to reach collective professional consciousness in the 1970s and the profession had begun
to respond by the 1980 and 1990s.
Perhaps the most devastating criticism came from Ivan Illich in his
1976 work Medical Nemesis. In his view, modern medicine only medicalises
disease, causing loss of health and wellness, while generally failing to restore
health by eliminating disease. The human being thus becomes a lifelong patient. Other less radical philosophers have
voiced similar views, but none were as virulent as Illich. (Another example can be found in Technopoly: The Surrender of
Culture to Technology by Neil Postman, 1992, which criticises overreliance on technological means in medicine.)
Criticism of modern medicine has led to some improvements in the curricula of medical schools, which now teach students
systematically on medical ethics, holistic approaches to medicine, the biopsychosocial model and similar concepts.
The inability of modern medicine to properly address many common complaints continues to prompt many people to seek support
from alternative medicine. Although most alternative
approaches lack scientific validation, many report improvement of symptoms after obtaining alternative therapies.
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