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

Patient-doctor reationship
The doctor-patient relationship and interaction is a central process in the practice of medicine. There are many perspectives from which understand and desribe 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 isymptoms, 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, 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 The patient-doctor relationship is additionally complicated by the patient's 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, ande 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 years medical care in the Western World has increasingly emphasized patient autonomy decision making.The relationship and process can also be analyzed in terms of social power relationships or economic transactions. Physicians have been accorded gradually higher status and respect the last century, and they have been entrusted with control of access to prescription medicines as a 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 years as costs of medical care have risen, and a third party 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 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-ctor 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
Main articles: Medical hisory, Physical examination.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 the reason for the current medical visit.
History of present illness the chronological order of events of symptoms. A mnemonic 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 ristory - birthplace, residences, marital history, social and economic status, habits
Family history- 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 made redundant by the availability of modern lab tests Four chief methods are used: inspection, palpation, percussion, and auscultation; smelling may be useful infection, uremia, diabetic ketoacidosis. The clinical examination involves study of:Vital signs include height, weight, body temperature, blood pressure, pulse, respiration rate, hemoglobin oxygen saturation

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 firsiagnosed or treated the patien Referrals are made for those patients who required the expertise or procedures performed by specialists. These include both ambulatory care and inpatiet 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 proved by specialist hospitals or regional centers equipped with diagnostic and treatment facilities not generally available at local hospitals. These include trauma centers, burn t centers, advnced neonatology unit sevices, organ transplants, high-risk pregnancy, radiation oncology, et.Modermedical care also depends on information - still delivered in many health care settingson paper records, but increasingly nowadays by electronic means.

Branches of medicine
Working together as an interdisciplinary team, many highly trained health professionals besides medical practitioners are involved in the delivery of modern health care. Some examples include: nses, laboratory scientists, pharmacists, physiotherapists, speech therapists, occupational therapists, dietitians and bioengineers.The scope and sciences underpinning human medicine overlap many other fields. Dentist and psychology, while separate disciplnes from medicine, are someties also considered medical fields. Physician assstants, 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, espcially 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. ology and physiology of the human brain.
Nutrition is the study of the relationship of food anrink 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 studyof 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 mcal technology degree, who actually perform the tests, assays, and procedures needed for providing the specific services. Transfusion medicine is concerned with the transfusion of blood and blood component, including the maintenance of a "blood bank".
Cellular pathology is concerned with diagnis using samples from ptients taken as tissues and cells using histology and cytology.
Clinical chemistry is ncerned with diosis by making biochemical analysis of blood, body fluids and tissues.
Hematology is concerned with diagnosis by looking at changes in the cellular composition of the blood and bone marrow as well as the coagulation system in the blood.

Clinical microbiologconcerned with disorders of immune system and related body defenses. It also deals with diagnosis of allergy.
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.