Preventive healthcare in the context of "Epidemiological"

Health care, or healthcare, is the improvement or maintenance of health via the prevention, diagnosis, treatment, amelioration or cure of disease, illness, injury, and other physical and mental impairments in people. Health care is delivered by health professionals and allied health fields. Medicine, dentistry, pharmacy, midwifery, nursing, optometry, audiology, psychology, occupational therapy, physical therapy, athletic training, and other health professions all constitute health care. The term includes work done in providing primary care, secondary care, tertiary care, and public health.

Access to health care may vary across countries, communities, and individuals, influenced by social and economic conditions and health policies. Providing health care services means "the timely use of personal health services to achieve the best possible health outcomes". Factors to consider in terms of health care access include financial limitations (such as insurance coverage), geographical and logistical barriers (such as additional transportation costs and the ability to take paid time off work to use such services), sociocultural expectations, and personal limitations (lack of ability to communicate with health care providers, poor health literacy, low income). Limitations to health care services affect negatively the use of medical services, the efficacy of treatments, and overall outcome (well-being, mortality rates).

Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population, and application of this knowledge to prevent diseases.

It is a cornerstone of public health, and shapes policy decisions and evidence-based practice by identifying risk factors for disease and targets for preventive healthcare. Epidemiologists help with study design, collection, and statistical analysis of data, amend interpretation and dissemination of results (including peer review and occasional systematic review). Epidemiology has helped develop methodology used in clinical research, public health studies, and, to a lesser extent, basic research in the biological sciences.

Community health refers to non-treatment based health services that are delivered outside hospitals and clinics. Community health is a subset of public health that is taught to and practiced by clinicians as part of their normal duties. Community health volunteers and community health workers work with primary care providers to facilitate entry into, exit from and utilization of the formal health system by community members as well as providing supplementary services such as support groups or wellness events that are not offered by medical institutions.

Community health is a major field of study within the medical and clinical sciences which focuses on the maintenance, protection, and improvement of the health status of population groups and communities, in particular those who are a part of disadvantaged communities. It is a distinct field of study that may be taught within a separate school of public health or preventive healthcare. The World Health Organization defines community health as:

Physical therapy (PT), also known as physiotherapy, is a healthcare profession, as well as the care provided by physical therapists. It focuses on promoting, maintaining, or restoring health through patient education, physical interventions, disease prevention, and health promotion. The term physical therapist or physiotherapist is used to represent the trained person providing physical therapy.

The profession has many specialties including musculoskeletal, orthopedics, cardiopulmonary, neurology, endocrinology, sports medicine, geriatrics, pediatrics, women's health, wound care and electromyography. PTs practice in many settings, both public and private.

A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via inhalation, injection, smoking, ingestion, absorption via a patch on the skin, suppository, or dissolution under the tongue.

A pharmaceutical drug, also called a medication or medicine, is a chemical substance used to treat, cure, prevent, or diagnose a disease or to promote well-being. Traditionally drugs were obtained through extraction from medicinal plants, but more recently also by organic synthesis. Pharmaceutical drugs may be used for a limited duration, or on a regular basis for chronic disorders.

Immunization, or immunisation, is the process by which an individual's immune system becomes fortified against an infectious agent (known as the immunogen). When this system is exposed to molecules that are foreign to the body, called non-self, it will orchestrate an immune response, and it will also develop the ability to quickly respond to a subsequent encounter because of immunological memory. This is a function of the adaptive immune system. Therefore, by exposing a human, or an animal, to an immunogen in a controlled way, its body can learn to protect itself: this is called active immunization. The most important elements of the immune system that are improved by immunization are the T cells, B cells, and the antibodies B cells produce. Memory B cells and memory T cells are responsible for a swift response to a second encounter with a foreign molecule. Passive immunization is direct introduction of these elements into the body, instead of production of these elements by the body itself.

Immunization happens in various ways, both in the wild and as done by human efforts in health care. Natural immunity is gained by those organisms whose immune systems succeed in fighting off a previous infection, if the relevant pathogen is one for which immunization is even possible. Natural immunity can have degrees of effectiveness (partial rather than absolute) and may fade over time (within months, years, or decades, depending on the pathogen). In health care, the main technique of artificial induction of immunity is vaccination, which is a major form of prevention of disease, whether by prevention of infection (pathogen fails to mount sufficient reproduction in the host), prevention of severe disease (infection still happens but is not severe), or both. Vaccination against vaccine-preventable diseases is a major relief of disease burden even though it usually cannot eradicate a disease. Vaccines against microorganisms that cause diseases can prepare the body's immune system, thus helping to fight or prevent an infection. The fact that mutations can cause cancer cells to produce proteins or other molecules that are known to the body forms the theoretical basis for therapeutic cancer vaccines. Other molecules can be used for immunization as well, for example in experimental vaccines against nicotine (NicVAX) or the hormone ghrelin in experiments to create an obesity vaccine.