Medicine

What is Medicine?

Medicine is the science and practice of caring for patients, managing diagnosis, prognosis, prevention, treatment, palliation of injury or disease, and promoting health. It encompasses various healthcare practices to maintain and restore health through preventive measures.

The Evolution of Medicine

Medicine has been practiced since prehistoric times, with early forms being an art connected to local culture and religious beliefs. Over time, medicine became a combination of art and science, incorporating modern scientific knowledge. Prescientific forms of medicine remain in use, known as alternative or traditional medicine, while treatments outside scientific medicine are termed quackery.

The Word ‘Medicine’

The word ‘medicine’ originates from Latin ‘medicus,’ meaning ‘a physician.’ Clinical practice varies globally due to cultural and technological differences. Modern scientific medicine is well-developed in the Western world but has limitations in developing countries.

Key Components of Medical Practice

In clinical practice, physicians assess patients using clinical judgment, examining medical history, performing physical examinations, ordering tests, prescribing treatments, and documenting patient interactions. They are in the patient’s own words and are recorded along with the duration of each one. Current activity: occupation, hobbies, what the patient actually does. Family history (FH): listing of diseases in the family that may impact the patient. History of present illness (HPI): the chronological order of events of symptoms and further clarification of each symptom. Distinguishable from history of previous illness, often called past medical history (PMH). Medications (Rx): what drugs the patient takes including prescribed, over-the-counter, and home remedies, as well as alternative and herbal medicines or remedies. Allergies are also recorded. Past medical history (PMH/PMHx): concurrent medical problems, past hospitalizations and operations, injuries, past infectious diseases or vaccinations, history of known allergies. Review of systems (ROS) or systems inquiry: a set of additional questions to ask, which may be missed on HPI. Social history (SH): birthplace, residences, marital history, social and economic status, habits (including diet, medications, tobacco, alcohol). The physical examination is the examination of the patient for medical signs of disease that are objective and observable. Four actions are the basis of physical examination: inspection, palpation, percussion, and auscultation. The clinical examination involves the study of: abdomen and rectum, cardiovascular, general appearance, genitalia, head, eye, ear, nose, and throat, musculoskeletal, neurological, psychiatric, respiratory, skin, vital signs. The treatment plan may include ordering additional medical laboratory tests and medical imaging studies, starting therapy, referral to a specialist, or watchful observation.

Healthcare Systems

The characteristics of health care systems impact how medical care is provided, with ancient Christian emphasis on charity leading to systematic nursing and hospitals. Most advanced industrial countries provide universal healthcare through single-payer or compulsory insurance systems, while tribal societies often rely on private payment or government financing.

Medical Care Categories

Medical care is classified into primary, secondary, and tertiary categories, with primary care focused on acute and chronic illnesses, preventive care, and health education. Secondary care involves specialist services, while tertiary care provides advanced services in specialist hospitals or regional centers.

The Role of Information Technology in Medicine

Modern medical care relies heavily on information, delivered electronically increasingly. In low-income countries, modern healthcare is often unaffordable, and international researchers advocate for removing user fees to ensure access. The separation of prescribing and dispensing is a practice where physicians and pharmacists are independent from each other. In Asian countries, it is traditional for physicians to also provide drugs.

Specializations in Medicine

The scope of human medicine overlaps with other fields such as nursing, laboratory science, pharmacy, and engineering. Physicians have various specializations and subspecializations into certain branches of medicine, including basic sciences, medical specialties, and interdisciplinary fields.

Basic Sciences

Basic sciences include: Anatomy (physical structure), Biochemistry (study of living organisms’ chemistry), Biomechanics (study of biological systems using mechanical methods), Biophysics (interdisciplinary study of biological systems), Biostatistics (application of statistics to biological fields). Other basic sciences include: Cytology (microscopic study of individual cells), Embryology (study of early development), Endocrinology (study of hormones and their effect on the body), Epidemiology (study of demographics of disease processes), Genetics (study of genes and biological inheritance), Gynecology (study of female reproductive system), Histology (study of biological tissues using light microscopy, electron microscopy, and immunohistochemistry), Immunology (study of the immune system) Medical physics is the study of applications of physics principles in medicine. Microbiology is the study of microorganisms. Molecular biology is the study of molecular processes. Neuroscience includes the study of the nervous system and its clinical specialties. Nutrition science studies the relationship between food and health, while dietetics focuses on practical application. Pathology is the study of disease causes and progression. Pharmacology studies drugs and their actions. Photobiology examines interactions between non-ionizing radiation and living organisms. Physiology studies normal body function and regulatory mechanisms. Radiobiology studies ionizing radiation interactions with living organisms. Toxicology studies hazardous effects of drugs and poisons.

Specialties in Medicine

Specialties include various branches of medicine, surgery, and other medical fields. Surgery is an ancient specialty that uses operative techniques to investigate or treat conditions. Other specialties may employ surgical procedures, but are not considered surgical sub-specialties. Requires a minimum of five years of residency after medical school for surgery, seven or more years for some sub-specialties, and one to three years for fellowships. Surgical subspecialties include bariatric surgery, cardiovascular surgery, colorectal surgery, and others. Internal medicine specialty focuses on adult diseases, with specialists called ‘internists’ in North America, while in other countries they are often called physicians. Internists may be subspecialized by organ system or age of patient. Diagnostic specialties include clinical laboratory sciences, which can be further divided into sub-specialties such as transfusion medicine and clinical neurophysiology. Diagnostic radiology is concerned with imaging the body using x-rays, computed tomography, ultrasonography, and nuclear magnetic resonance tomography.

Nuclear Medicine

Nuclear medicine studies human organ systems by administering radiolabelled substances to be imaged outside the body.

Other Major Medical Specialties

Other major medical specialties include: Anesthesiology, Emergency medicine, Family medicine, Medical genetics, Neurology, Obstetrics and gynecology, Pediatrics, Pharmaceutical medicine, Physical medicine and rehabilitation, Podiatric medicine. Preventive medicine prevents disease. Community health involves population health analysis to maintain community health. Psychiatry studies cognitive, perceptual, emotional and behavioral disorders.

Interdisciplinary Fields in Medicine

Interdisciplinary fields include: Addiction, aerospace, biomedical engineering, clinical pharmacology, Conservation, disaster, diving, evolutionary, forensic, gender-based, health informatics, hospice and palliative, hospital medicine, laser medicine, Medical ethics, medical humanities, nosokinetics, nosology, occupational medicine, pain management, pharmacogenomics. Podiatric medicine: study, diagnosis & treatment of foot disorders. Sexual medicine: diagnosis & treatment of sexual disorders. Sports medicine: prevention & rehabilitation of sports injuries. Therapeutics: various remedies for treating disease & promoting health. Travel medicine: health problems of international travelers. Tropical medicine: prevention & treatment of tropical diseases. Urgent care: delivery of unscheduled, walk-in care for non-emergency medical conditions. Veterinary medicine: care of non-human animals. Wilderness medicine: practice of medicine in the wild.

Medical Education and Training

Medical education and training vary worldwide, typically involving university medical school, internship/residency, and postgraduate training. Doctors must complete a recognized degree (M.D. or D.O.) and pass exams to become licensed/registered. Continuing medical education is often required due to rapid knowledge & technology advancements. Regulatory authorities require licensure for medical doctors in most countries.

Medical Ethics

Medical ethics encompasses moral principles that apply values and judgments to medicine, including autonomy, beneficence, justice, non-maleficence, respect for persons, truthfulness, and honesty. These values provide a framework for understanding conflicts but do not always provide answers on how to handle particular situations.

The History of Medicine

Prehistoric medicine used plants, animal parts, and minerals ritually as magical substances by priests, shamans, or medicine men. The earliest known medical texts were found in ancient Syria and date back to 2500 BCE. Other early records of medicine come from ancient Egypt, Babylonian Medicine, Ayurvedic medicine, classical Chinese medicine, and ancient Greek medicine.

Key Medical Texts

In the European Union, access and exercise as a doctor are regulated by the Directive 2005/36/EC. Doctors can face charges of medical malpractice if they are negligent or intentionally harmful to patients. The oldest Egyptian medical text is the Kahun Gynaecological Papyrus from around 2000 BCE. The Edwin Smith Papyrus (1600 BCE) is an early work on surgery, while the Ebers Papyrus (1500 BCE) is a comprehensive textbook on medicine. In China, the Bronze Age Shang dynasty saw evidence of seeds for herbalism and tools presumed to have been used for surgery. The Huangdi Neijing (2nd century BCE – 3rd century CE) is an ancient medical text that compiles Chinese medicine.

Contributions to Medicine

In India, the surgeon Sushruta described numerous surgical operations, including plastic surgery. Earliest records of dedicated hospitals come from Mihintale in Sri Lanka. In Greece, Hippocrates laid the foundation for modern medicine and introduced the Hippocratic Oath. The Greek physician Galen performed many audacious operations and wrote a comprehensive medical text.

The Concept of Hospital

The concept of hospital as an institution to offer medical care emerged in the Byzantine Empire. The Islamic world translated ancient Greek texts into Arabic and made significant contributions to medicine, including Avicenna’s ‘Canon of Medicine.’ Persian physicians like Rhazes questioned Greek theories and made significant discoveries in surgery and pediatrics.

Modern Science and Medicine

In Europe, Charlemagne decreed that hospitals be attached to cathedrals and monasteries. The Catholic Church funded these hospitals through taxes and estates, providing food for the population during famine and distributing it to the poor. This welfare system was an early version of a state-funded healthcare system. The Benedictine order established hospitals and medical schools. The Church networked cathedral schools for medicine study. The Schola Medica Salernitana was the finest medical school in Medieval Europe.

The Black Death

The Black Death devastated Western Europe but led to early figures in medicine emerging. A shift occurred from traditional authority to scientific thinking, with physicians improving upon past theories. Andreas Vesalius wrote De humani corporis fabrica and observed bacteria with a microscope.

Modern Biotechnology and Medicine

Modern science and medicine developed with the discovery of microorganisms, pulmonary circulation, and vaccines. Veterinary medicine was separated from human medicine in 1761. Modern biomedical research replaced early Western traditions based on herbalism and pre-modern notions.

Groundbreaking Researchers

Groundbreaking researchers made notable contributions to medicine, including Edward Jenner, Robert Koch, Alexander Fleming, Florence Nightingale, Santiago Ramón y Cajal, Maurice Wilkins, Howard Florey, and many others. Medications developed from plant products, animal body parts, and fluids became more reliant upon pharmaceuticals. Vaccines were discovered by Edward Jenner and Louis Pasteur. The first antibiotic 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 German chemists originally from azo dyes.

The Role of Pharmacology

Pharmacology has become increasingly sophisticated; modern biotechnology allows drugs targeted towards specific physiological processes to be developed, sometimes designed for compatibility with the body to reduce side-effects. Genomics and knowledge of human genetics and human evolution is having increasingly significant influence on medicine. Evidence-based medicine is a contemporary movement to establish the most effective algorithms of practice through the use of systematic reviews and meta-analysis.

The Cochrane Collaboration

The Cochrane Collaboration leads this movement. A 2001 review of 160 Cochrane systematic reviews revealed that, according to two readers, 21.3% of the reviews concluded insufficient evidence, 20% concluded evidence of no effect, and 22.5% concluded positive effect.

Modern Medical Systems

Evidence-based medicine, prevention of medical error (and other ‘iatrogenesis’), and avoidance of unnecessary health care are a priority in modern medical systems. These topics generate significant political and public policy attention, particularly in the United States where healthcare is regarded as excessively costly but population health metrics lag similar nations.

Global Healthcare Challenges

Globally, many developing countries lack access to care and access to medicines. As of 2015, most wealthy developed countries provide health care to all citizens, with a few exceptions such as the United States where lack of health insurance coverage may limit access.

Medicine, a field that has evolved from ancient rituals and beliefs into a sophisticated science, continues to shape our understanding of health and disease. From the earliest forms of healing in prehistoric times to the cutting-edge technologies of today, medicine remains at the forefront of human progress. As we continue to explore new frontiers in healthcare, it is crucial to remember that behind every medical breakthrough lies a commitment to improving lives and ensuring the well-being of humanity.