History of medicineThe earliest type of medicine in most cultures was the use of empirical natural resources like plants (herbalism, animal parts and minerals. In all societies, even in Western ones, there were also religious, ritual and magical resources. In aboriginal societies, there is a large scope of medical systems related to religious thinking, cultural experience, and natural resources. The religious ones more known are : animism (the notion of inanimate objects having spirits); spiritualism (here meaning an appeal to gods or communion with ancestor spirits); shamanism (the vesting of an individual with mystic powers); and divination (the supposed obtaining of truth by magic means). The field of medical anthropology studies the various medical systems and their interaction with society.
The practice of medicine developed gradually in ancient Egypt, Babyl
onia, India, China, Greece, Persia, the Islamic world, medieval Europe, and elsewhere. Medicine as it is now practiced largely developed during the Middle Ages and early modern period in Persia (Rhazes and Avicenna), Spain (Abulcasis and Avenzoar), Syria/Egypt (Ibn al-Nafis, 13th century), England (William Harvey, 17th century), Germany (Rudolf Virchow, 19th century) and France (Jean-Martin Charcot, Claude Bernard and others). The new "scientific" or "experimental" medicine (where results are testable and repeatable) replaced early Western traditions of medicine, based on herbalism, the Greek "four humours" and other pre-modern theories.
The focal points of development of clinical medicine shifted to the United Kingdom and the USA by the early 1900s (Canadian-born) Sir William Osler, Harvey Cushing). Possibly the major shift in medical thinking was the gradual rejection, especially during the Black Death in the 14th and 15th centuries, of what may be called the 'traditional authority' approach to science and medicine. This was the notion that because some prominent person in the past said something must be so, then that was the way it was, and anything one observed to the contrary was an anomaly (which was paralleled by a similar shift in European society in general - see Copernicus's rejection of Ptolemy's theories on astronomy). People like Ibn al-Nafis and Vesalius led the way in improving upon or indeed rejecting the theories of great authorities from the past such as Hippocrates, Galen, and Avicenna, many of whose theories were in time discredited. Such new attitudes were made possible in Europe by the weakening of the Roman Catholic church's power in society, especially in the Republic of Venice.
Evidence-based medicine is a recent movement to establish the most effective algorithms of practice (ways of doing things) through the use of the scientific method and modern global information science by collating all the evidence and developing standard protocols which are then disseminated to healthcare providers. One problem with this 'best practice' approach is that it could be seen to stifle novel approaches to treatment.
Drug ampoules
The practice of medicine developed gradually in ancient Egypt, Babyl
onia, India, China, Greece, Persia, the Islamic world, medieval Europe, and elsewhere. Medicine as it is now practiced largely developed during the Middle Ages and early modern period in Persia (Rhazes and Avicenna), Spain (Abulcasis and Avenzoar), Syria/Egypt (Ibn al-Nafis, 13th century), England (William Harvey, 17th century), Germany (Rudolf Virchow, 19th century) and France (Jean-Martin Charcot, Claude Bernard and others). The new "scientific" or "experimental" medicine (where results are testable and repeatable) replaced early Western traditions of medicine, based on herbalism, the Greek "four humours" and other pre-modern theories.The focal points of development of clinical medicine shifted to the United Kingdom and the USA by the early 1900s (Canadian-born) Sir William Osler, Harvey Cushing). Possibly the major shift in medical thinking was the gradual rejection, especially during the Black Death in the 14th and 15th centuries, of what may be called the 'traditional authority' approach to science and medicine. This was the notion that because some prominent person in the past said something must be so, then that was the way it was, and anything one observed to the contrary was an anomaly (which was paralleled by a similar shift in European society in general - see Copernicus's rejection of Ptolemy's theories on astronomy). People like Ibn al-Nafis and Vesalius led the way in improving upon or indeed rejecting the theories of great authorities from the past such as Hippocrates, Galen, and Avicenna, many of whose theories were in time discredited. Such new attitudes were made possible in Europe by the weakening of the Roman Catholic church's power in society, especially in the Republic of Venice.
Evidence-based medicine is a recent movement to establish the most effective algorithms of practice (ways of doing things) through the use of the scientific method and modern global information science by collating all the evidence and developing standard protocols which are then disseminated to healthcare providers. One problem with this 'best practice' approach is that it could be seen to stifle novel approaches to treatment.
Drug ampoules
Genomics and knowledge of human genetics is already having some influence on medicine, as the causative genes of most monogenic genetic disorders have now been identified, and the development of techniques in molecular biology and genetics are influencing medical practice and decision-making.
Pharmacology has developed from herbalism and many drugs are still derived from plants (atropine, ephedrine, warfarin, aspirin, digoxin, vinca alkaloids, taxol, hyoscine, etc). The modern era began with Robert Koch's discoveries around 1880 of the transmission of disease by bacteria, and then the discovery of antibiotics shortly thereafter around 1900. The first of these was arsphenamine / Salvarsan discovered by Paul Ehrlich in 1908 after he observed that bacteria took up toxic dyes that human cells did not. The first major class of antibiotics was the sulfa drugs, derived by French chemists originally from azo dyes. Throughout the twentieth century, major advances in the treatment of infectious diseases were observable in (Western) societies. The medical establishment is now developing drugs targeted towards one particular disease process. Thus drugs are being developed to minimise the side effects of prescribed drugs, to treat cancer, geriatric problems, long-term problems (such as high cholesterol), chronic diseases type 2 diabetes, lifestyle and degenerative diseases such as arthritis and Alzheimer's disease.
Practice of medicine
Artificial biomedical insemination
The practice of medicine combines both science as the evidence base and art in the application of this medical knowledge in combination with intuition and clinical judgment to determine the treatment plan for each patient.
Central to medicine is the patient-physician relationship established when a person with a health concern seeks a physician's help; the 'medical encounter'. Other health professionals similarly establish a relationship with a patient and may perform various interventions, e.g. nurses, radiographers and therapists.
As part of the medical encounter, the healthcare provider needs to:
develop a relationship with the patient
gather data (medical history, systems enquiry, and physical examination, combined with laboratory or imaging studies (investigations))
analyze and synthesize that data (assessment and/or differential diagnoses), and then:
develop a treatment plan (further testing, therapy, watchful observation, referral and follow-up)
treat the patient accordingly
assess the progress of treatment and alter the plan as necessary (management).
The medical encounter is documented in a medical record, which is a legal document in many jurisdictions.
Health care delivery systems
Medicine is practiced within the medical system, which is a legal, credentialing and financing framework, established by a particular culture or government. The characteristics of a health care system have significant effect on the way medical care is delivered.
Most industrialized countries and many developing countries deliver health care though a system of universal health care which guarantees health care for all through a system of compulsory private or co-operative health insurance funds or via government backed social insurance. This insurance, (in effect, a form of taxation) ensures the entire population has access to medical care on the basis of need rather than ability to pay. The delivery systems may be provided by private medical practices or by state owned hospitals and clinics, or by charities.
Most tribal societies but also some communist countries (e.g. China) and at least one industrialized capitalist country (the United States) provide no guarantee of health care for the population as a whole. In such societies, health care is available to those that can afford to pay for it or have self insured it (either directly or as part of an employment contract) or who may be covered by care financed by the government or tribe directly.
Transparency of information is another factor defining a delivery system. Access to information on conditions, treatments, quality and pricing greatly affects the choice by patients / consumers and therefore the incentives of medical professionals. While US health care system has come under fire for lack of openness, new legislation may encourage greater openness. There is a perceived tension between the need for transparency on the one hand and such issues as patient confidentiality and the possible exploitation of information for commercial gain on the other.
Health care delivery
Most industrialized countries and many developing countries deliver health care though a system of universal health care which guarantees health care for all through a system of compulsory private or co-operative health insurance funds or via government backed social insurance. This insurance, (in effect, a form of taxation) ensures the entire population has access to medical care on the basis of need rather than ability to pay. The delivery systems may be provided by private medical practices or by state owned hospitals and clinics, or by charities.
Most tribal societies but also some communist countries (e.g. China) and at least one industrialized capitalist country (the United States) provide no guarantee of health care for the population as a whole. In such societies, health care is available to those that can afford to pay for it or have self insured it (either directly or as part of an employment contract) or who may be covered by care financed by the government or tribe directly.
Transparency of information is another factor defining a delivery system. Access to information on conditions, treatments, quality and pricing greatly affects the choice by patients / consumers and therefore the incentives of medical professionals. While US health care system has come under fire for lack of openness, new legislation may encourage greater openness. There is a perceived tension between the need for transparency on the one hand and such issues as patient confidentiality and the possible exploitation of information for commercial gain on the other.
Health care delivery
Medical care delivery is classified into primary, secondary and tertiary care.
Primary care medical services are provided by physicians or other health professionals who have first contact with a patient seeking medical treatment or care. These occur in physician offices, 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 sexes.
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.
Primary care medical services are provided by physicians or other health professionals who have first contact with a patient seeking medical treatment or care. These occur in physician offices, 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 sexes.
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
Physicians have many specializations and subspecializations into certain branches of medicine, which are listed below. There are variations from country to country regarding which specialties certain subspecialties are in.
Physicians have many specializations and subspecializations into certain branches of medicine, which are listed below. There are variations from country to country regarding which specialties certain subspecialties are in.
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 immunohistochemistry.
Immunology is the study of the immune system, which includes the innate and adaptive immune system in humans, for example.
Microbiology is the study of microorganisms, including protozoa, bacteria, fungi, and viruses.
Neuroscience includes 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 and spinal cord.
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 as a science 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.
Medical specialties
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 immunohistochemistry.
Immunology is the study of the immune system, which includes the innate and adaptive immune system in humans, for example.
Microbiology is the study of microorganisms, including protozoa, bacteria, fungi, and viruses.
Neuroscience includes 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 and spinal cord.
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 as a science 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.
Medical specialties
Medical speciality
In the broadest meaning of 'medicine', there are many different specialties, which additionally have many sub-specialties. However, within medical circles, medicine usually denotes doctors that specialise in one internal medicine specialties, as opposed to surgery or radiology. The various specialties can be categorised thus:
Surgical specialities - the use of manually operative and instrumental techniques to treat disorders.
Internal medicine - concerns the diagnosis and nonsurgical treatment of diseases in adults, especially of internal organs.
Diagnostic specialties, rather examines disorders (especially imaging specialities) than directly attempts to cure.
Anaesthetics - specialise in anaesthetising patients for procedures and optimising analgesia
Surgical
In the broadest meaning of 'medicine', there are many different specialties, which additionally have many sub-specialties. However, within medical circles, medicine usually denotes doctors that specialise in one internal medicine specialties, as opposed to surgery or radiology. The various specialties can be categorised thus:
Surgical specialities - the use of manually operative and instrumental techniques to treat disorders.
Internal medicine - concerns the diagnosis and nonsurgical treatment of diseases in adults, especially of internal organs.
Diagnostic specialties, rather examines disorders (especially imaging specialities) than directly attempts to cure.
Anaesthetics - specialise in anaesthetising patients for procedures and optimising analgesia
Surgical
Surgical specialties employ operative treatment. Some disciplines are highly specialized and are often not considered subdisciplines of surgery, although their naming might suggest so.
It has many subspecialties, e.g. general surgery, cardiovascular surgery, maxillofacial surgery, orthopedic surgery, otolaryngology, plastic surgery, oncologic surgery, vascular surgery and pediatric surgery.
In some centres, anesthesiology is part of the division of surgery (for logistical and planning purposes), although it certainly is not a surgical discipline.
Internal medicine
It has many subspecialties, e.g. general surgery, cardiovascular surgery, maxillofacial surgery, orthopedic surgery, otolaryngology, plastic surgery, oncologic surgery, vascular surgery and pediatric surgery.
In some centres, anesthesiology is part of the division of surgery (for logistical and planning purposes), although it certainly is not a surgical discipline.
Internal medicine
Internal medicine is concerned with systemic diseases of adults, i.e. those diseases that affect the body as a whole (restrictive, current meaning), or with all adult non-operative somatic medicine (traditional, inclusive meaning), thus excluding pediatrics, surgery, gynaecology and obstetrics, and psychiatry. Practitioners of such specialties are referred to as Physicians. There are several subdisciplines of internal medicine:
Cardiology
Critical care medicine
Endocrinology
Gastroenterology
Hepatology
Hematology
Infectious diseases
Nephrology
Oncology
Proctology
Pulmonology
Rheumatology
Neurology
Geriatrics
Diagnostic specialties
Cardiology
Critical care medicine
Endocrinology
Gastroenterology
Hepatology
Hematology
Infectious diseases
Nephrology
Oncology
Proctology
Pulmonology
Rheumatology
Neurology
Geriatrics
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. Subspecialties include Transfusion medicine, Cellular pathology, Clinical chemistry, Hematology, Clinical microbiology and Clinical immunology.
pathology as a medical specialty is the branch of medicine that deals with the study of diseases and the morphologic, physiologic changes produced by them. As a diagnostic specialty, pathology can be considered the basis of modern scientific medical knowledge and plays a large role in evidence-based medicine. Many modern molecular tests such as flow cytometry, polymeras chain reaction (PCR), immunohistochemistry, cytogenetics, gene rearragements studies and fluorescent in situ hybridization (FISH) fall within the territory of pathology.
Radiology is concerned with imaging of the human body, e.g. by x-rays, x-ray ultrasonography, and nuclear magnetic resonance tomography.
Clinical Neurophysiology is concerned with testing the physiology or function of the central and peripheral aspects of the nervous system. These kinds of tests can be divided into recordings of: (1) spontaneous or continuously running electrical activity, or (2) stimulus evoked responses. Subspecialities include Electroencephalography, Electromyography, Evoked potential, Nerve conduction study and Polysomnography.
pathology as a medical specialty is the branch of medicine that deals with the study of diseases and the morphologic, physiologic changes produced by them. As a diagnostic specialty, pathology can be considered the basis of modern scientific medical knowledge and plays a large role in evidence-based medicine. Many modern molecular tests such as flow cytometry, polymeras chain reaction (PCR), immunohistochemistry, cytogenetics, gene rearragements studies and fluorescent in situ hybridization (FISH) fall within the territory of pathology.
Radiology is concerned with imaging of the human body, e.g. by x-rays, x-ray ultrasonography, and nuclear magnetic resonance tomography.
Clinical Neurophysiology is concerned with testing the physiology or function of the central and peripheral aspects of the nervous system. These kinds of tests can be divided into recordings of: (1) spontaneous or continuously running electrical activity, or (2) stimulus evoked responses. Subspecialities include Electroencephalography, Electromyography, Evoked potential, Nerve conduction study and Polysomnography.
