Health science

"Biomedical science" redirects here. For other uses, see Branches of medicine.

Health science or biomedical science is the applied science dealing with health.

There are two approaches to health science: the study and research of the food that we eat; and the study and research of health-related issues to understand how humans and other animals function, and the application of that knowledge to improve health and to prevent and curediseases.

Health research builds upon the natural sciences of biology, chemistry, and physics as well as a variety of multidisciplinary fields. Some of the other primarily research-oriented fields that make contributions to health science are biochemistry, epidemiology, genetics, and pharmacology(for a more comprehensive list, see List of health science disciplines).

A myriad of applied health specializations and professions also endeavor to better understand health, but in addition they try to directly improve the health of individuals and of people in general, as well as of other animals (see veterinary medicine). Some of these are: alternative medicine,biomedical engineering, biotechnology, clinical laboratory science, medicine, nursing, nutrition, pharmacy, public health, psychology, andphysical therapy. The provision of services to improve people's health is referred to as health care.

The health sciences industry, a multi-billion dollar business sector, is a cross-section of the life sciences and the health care and medical diagnostics industries.

Naturopathy

Naturopathy (also known as naturopathic medicine or natural medicine) is an eclectic alternative medical system that focuses on natural remedies and the body's vital ability to heal and maintain itself. Naturopathic philosophy favors a holistic approach and minimal use of surgery and drugs. Naturopathy comprises many different treatment modalities of varying degrees of acceptance by the medical community; diet and lifestyle advice may be substantially similar to that offered by non-naturopaths, and acupuncture may help reduce pain in some cases, while homeopathy is often characterized as pseudoscience or quackery.^{[1][2][3][4][5]} Evidence-based medicine (EBM) has been advocated as an appropriate methodology for determining the scientific basis of naturopathy.^[6] Naturopaths have opposed vaccination based in part in the early philosophies which shaped the profession.^[7]

Naturopathy has its origins in the Nature Cure movement of Europe.^[8][9] The term was coined in 1895 by John Scheel and popularized by Benedict Lust,^[10] the "father of U.S. naturopathy".^[11] Beginning in the 1970s, there was a revival of interest in the United States and Canada in conjunction with the holistic health movement.^[1][11]

Naturopathy is practiced in many countries, especially the United States and Canada, and is subject to different standards of regulation and levels of acceptance. Naturopathic medicine is a recent manifestation of the field of naturopathy, a 19th-century health movement espousing "the healing power of nature." Naturopathic physicians now claim to be primary care physicians proficient in the practice of both conventional and natural medicine. Their training, however, amounts to a small fraction of that of medical doctors who practice primary care.^[12] In the United States and Canada, the designation of Naturopathic Doctor (ND) may be awarded after completion of a four year program of study at an accredited Naturopathic medical school that includes the study of basic medical sciences as well as natural remedies and medical care.^{[13][14][neutrality is disputed]} The scope of practice varies widely between jurisdictions, and naturopaths in unregulated jurisdictions may use the Naturopathic Doctor designation or other titles regardless of level of education.^[15]

Chiropractic

Chiropractic is a health care discipline and profession that emphasizes diagnosis, treatment and prevention of mechanical disorders of the musculoskeletal system, especially the spine, under the hypothesis that these disorders affect general health via the nervous system.^[1] It is generally categorized as complementary and alternative medicine (CAM),^[2] a characterization that many chiropractors reject.^[3] The main chiropractic treatment technique involves manual therapy, including manipulation of the spine, other joints, and soft tissues; treatment also includes exercises and health and lifestyle counseling.^[4] Traditional chiropractic assumes that avertebral subluxation or spinal joint dysfunction interferes with the body's function and its innate intelligence,^[5] a vitalistic notion that brings ridicule from mainstream science and medicine.^[6]

D.D. Palmer founded chiropractic in the 1890s and his son B.J. Palmer helped to expand it in the early 20th century.^[7] It has two main groups: "straights", now the minority, emphasize vitalism, Innate Intelligence and spinal adjustments, and consider subluxations to be the leading cause of all disease; "mixers" are more open to mainstream and alternative medical techniques such as exercise, massage,nutritional supplements, and acupuncture.^[8] Chiropractic is well established in the U.S., Canada and Australia.^[9]

Throughout its history it has been controversial.^[10][11] For most of its existence, chiropractic has battled with mainstream medicine, sustained by ideas such as subluxation^[12] that are not based on solid science.^[13] Vaccination remains controversial among chiropractors.^[14] The American Medical Association called chiropractic an "unscientific cult"^[15] and boycotted it until losing a 1987 antitrustcase.^[16] Chiropractic has had a strong political base and sustained demand for services; in recent decades, it has gained more legitimacy and greater acceptance among medical physicians and health plans in the U.S.,^[16] and evidence-based medicine has been used to review research studies and generate practice guidelines.^[17] Many studies of treatments used by chiropractors have been conducted, with conflicting results. Collectively, systematic reviews of this research have not demonstrated that spinal manipulation is effective, with the possible exception of treatment of back pain.^[13] The efficacy and cost-effectiveness of maintenance chiropractic care are unknown.^[18]Although spinal manipulation can have serious complications in rare cases,^[19][20] chiropractic care is generally safe when employed skillfully and appropriately.^[21]

Health And Beauty: Bread, cereals and other starchy foods

Your weight

Expert advice to help you maintain a healthy weight

Dissatisfied with your weight?

We're bombarded with scare stories about weight, from size zero to the obesity 'epidemic'. But a healthy weight is determined by different factors for each of us. Our expert advice is designed to help you achieve and maintain a healthy, life-enhancing weight.

Overweight or underweight?

Being the right weight has a positive effect on wellbeing but also on our health, as being the wrong weight can cause a range of medical problems.

This food group is your body's main source of energy and contains bread, pasta, rice, potatoes, noodles, chapatti, cereals and other starchy carbohydrates.

Refined and unrefined grains

The foods listed above (apart from potatoes) are all produced from grains, such as wheat, corn or rice. They should be a part of all meals, filling about a third of your plate. They can come in two forms – refined or unrefined (often known as whole grains).

Refined grains have been stripped of their outer bran coating and inner germ during the milling process, leaving only the endosperm. They include white rice, white bread and white pasta.

In a whole grain the bran, germ and endosperm are all still present. The bran is an excellent source of fibre; the germ is a source of protein, vitamins and minerals; and the endosperm supplies most of the carbohydrates, mainly in the form of starch. Unrefined or whole grain forms provide far more nutrients than their unrefined counterparts.

Whole grains are rich in phytochemicals and antioxidants, which help to protect against coronary heart disease, certain cancers, and diabetes. Studies have shown people who eat more whole grains tend to have a healthier heart.

Most people get their whole grain from wholemeal bread or whole grain breakfast cereals such as porridge, muesli or whole wheat cereals. Choose a whole grain variety over processed or refined grains, and look out for added sugar or salt.

Health And Beauty: Tackling nutritional problems for older people

Your weight

Expert advice to help you maintain a healthy weight

Dissatisfied with your weight?

We're bombarded with scare stories about weight, from size zero to the obesity 'epidemic'. But a healthy weight is determined by different factors for each of us. Our expert advice is designed to help you achieve and maintain a healthy, life-enhancing weight.

Overweight or underweight?

Being the right weight has a positive effect on wellbeing but also on our health, as being the wrong weight can cause a range of medical problems.

Maintaining health as we age can be challenging, so a diet rich in nutrients is increasingly important as we grow older.

Factors that affect nutrition

There are many factors that influence nutritional status in older adults, and they can be broadly grouped into four main areas:

Those that naturally occur during the ageing process, such as a reduced ability to absorb nutrients efficiently, or a sore mouth due to dentures

Disease-specific conditions such as cancer, which place greater nutritional demands on people

Some drugs that interact with nutrients and prevent absorption, for example aspirin, which can interfere with the absorption of vitamin C

Social influences, such as not being able to get to shops, or social isolation

Continuing to enjoy food and to eat a diet that maintains nutritional status is key to coping with illness. Poor nutrition has been shown to increase the risk of infections, bed sores, chest infections and poor wound healing. Good nutritional status will help ensure a quicker recovery.

Health Insurance

Health insurance is insurance that pays for medical expenses. It is sometimes used more broadly to include insurance covering disability orlong-term nursing or custodial care needs. It may be provided through a government-sponsored social insurance program, or from private insurance companies. It may be purchased on a group basis (e.g., by a firm to cover its employees) or purchased by individual consumers. In each case, the covered groups or individuals pay premiums or taxes to help protect themselves from high or unexpected healthcare expenses. Similar benefits paying for medical expenses may also be provided through social welfare programs funded by the government.

By estimating the overall risk of healthcare expenses, a routine finance structure (such as a monthly premium or annual tax) can be developed, ensuring that money is available to pay for the healthcare benefits specified in the insurance agreement. The benefit is administered by a central organization such as a government agency, private business, or not-for-profit entity.^[1]

How it works

A health insurance policy is a contract between an insurance company and an individual or his sponsor (e.g. an employer). The contract can be renewable annually or monthly. The type and amount of health care costs that will be covered by the health insurance company are specified in advance, in the member contract or "Evidence of Coverage" booklet. The individual insurered person's obligations may take several forms:^[8]

• Premium: The amount the policy-holder or his sponsor (e.g. an employer) pays to the health plan each month to purchase health coverage.
• Deductible: The amount that the insured must pay out-of-pocket before the health insurer pays its share. For example, a policy-holder might have to pay a $500 deductible per year, before any of their health care is covered by the health insurer. It may take several doctor's visits or prescription refills before the insured person reaches the deductible and the insurance company starts to pay for care.
• Copayment: The amount that the insured person must pay out of pocket before the health insurer pays for a particular visit or service. For example, an insured person might pay a $45 copayment for a doctor's visit, or to obtain a prescription. A copayment must be paid each time a particular service is obtained.
• Coinsurance: Instead of, or in addition to, paying a fixed amount up front (a copayment), the co-insurance is a percentage of the total cost that insured person may also pay. For example, the member might have to pay 20% of the cost of a surgery over and above a co-payment, while the insurance company pays the other 80%. If there is an upper limit on coinsurance, the policy-holder could end up owing very little, or a great deal, depending on the actual costs of the services they obtain.
• Exclusions: Not all services are covered. The insured person is generally expected to pay the full cost of non-covered services out of their own pocket.
• Coverage limits: Some health insurance policies only pay for health care up to a certain dollar amount. The insured person may be expected to pay any charges in excess of the health plan's maximum payment for a specific service. In addition, some insurance company schemes have annual or lifetime coverage maximums. In these cases, the health plan will stop payment when they reach the benefit maximum, and the policy-holder must pay all remaining costs.
• Out-of-pocket maximums: Similar to coverage limits, except that in this case, the insured person's payment obligation ends when they reach the out-of-pocket maximum, and the health company pays all further covered costs. Out-of-pocket maximums can be limited to a specific benefit category (such as prescription drugs) or can apply to all coverage provided during a specific benefit year.
• Capitation: An amount paid by an insurer to a health care provider, for which the provider agrees to treat all members of the insurer.
• In-Network Provider: (U.S. term) A health care provider on a list of providers preselected by the insurer. The insurer will offer discounted coinsurance or copayments, or additional benefits, to a plan member to see an in-network provider. Generally, providers in network are providers who have a contract with the insurer to accept rates further discounted from the "usual and customary" charges the insurer pays to out-of-network providers.
• Prior Authorization: A certification or authorization that an insurer provides prior to medical service occurring. Obtaining an authorization means that the insurer is obligated to pay for the service, assuming it matches what was authorized. Many smaller, routine services do not require authorization.^[9]
• Explanation of Benefits: A document sent by an insurer to a patient explaining what was covered for a medical service, and how they arrived at the payment amount and patient responsibility amount.^[10]

Prescription drug plans are a form of insurance offered through some employer benefit plans in the U.S., where the patient pays a copayment and the prescription drug insurance part or all of the balance for drugs covered in the formulary of the plan.

Some, if not most, health care providers in the United States will agree to bill the insurance company if patients are willing to sign an agreement that they will be responsible for the amount that the insurance company doesn't pay. The insurance company pays out of network providers according to "reasonable and customary" charges, which may be less than the provider's usual fee. The provider may also have a separate contract with the insurer to accept what amounts to a discounted rate or capitation to the provider's standard charges. It generally costs the patient less to use an in-network provider.

Swine Influenza

Swine influenza (also called H1N1 flu, swine flu, hog flu, and pig flu) is an infection by any one of several types of swine influenza virus. Swine influenza virus (SIV) is any strain of the influenza family of viruses that is endemic in pigs.^[2] As of 2009, the known SIV strains include influenza C and the subtypes of influenza A known as H1N1, H1N2, H3N1, H3N2, and H2N3.

Swine influenza virus is common throughout pig populations worldwide. Transmission of the virus from pigs to humans is not common and does not always lead to human influenza, often resulting only in the production of antibodies in the blood. If transmission does cause human influenza, it is called zoonotic swine flu. People with regular exposure to pigs are at increased risk of swine flu infection. The meat of an infected animal poses no risk of infection when properly cooked.

During the mid-20th century, identification of influenza subtypes became possible, allowing accurate diagnosis of transmission to humans. Since then, only 50 such transmissions have been confirmed. These strains of swine flu rarely pass from human to human. Symptoms of zoonotic swine flu in humans are similar to those of influenza and of influenza-like illness in general, namely chills, fever, sore throat, muscle pains, severe headache, coughing, weakness and general discomfort.

Signs and symptoms

In swine

In pigs influenza infection produces fever, lethargy, sneezing, coughing, difficulty breathing and decreased appetite.^[11] In some cases the infection can cause abortion. Although mortality is usually low (around 1-4%),^[2] the virus can produce weight loss and poor growth, causing economic loss to farmers.^[11] Infected pigs can lose up to 12 pounds of body weight over a 3 to 4 week period.^[11]

In humans

Main symptoms of swine flu in humans^[65]

Direct transmission of a swine flu virus from pigs to humans is occasionally possible (called zoonotic swine flu). In all, 50 cases are known to have occurred since the first report in medical literature in 1958, which have resulted in a total of six deaths.^[66] Of these six people, one was pregnant, one had leukemia, one had Hodgkin disease and two were known to be previously healthy.^[66] Despite these apparently low numbers of infections, the true rate of infection may be higher, since most cases only cause a very mild disease, and will probably never be reported or diagnosed.^[66]

In this video, Dr. Joe Bresee, with CDC's Influenza Division, describes the symptoms of swine flu and warning signs to look for that indicate the need for urgent medical attention.
See also: See this video with subtitles on YouTube [1]

According to the Centers for Disease Control and Prevention (CDC), in humans the symptoms of the 2009 "swine flu" H1N1 virus are similar to those of influenza and of influenza-like illness in general. Symptoms include fever, cough, sore throat, body aches, headache, chills and fatigue. The 2009 outbreak has shown an increased percentage of patients reporting diarrhea and vomiting.^[67] The 2009 H1N1 virus is not zoonotic swine flu, as it is not transmitted from pigs to humans, but from person to person.

Because these symptoms are not specific to swine flu, a differential diagnosis of probable swine flu requires not only symptoms but also a high likelihood of swine flu due to the person's recent history. For example, during the 2009 swine flu outbreak in the United States, CDC advised physicians to "consider swine influenza infection in the differential diagnosis of patients with acute febrile respiratory illness who have either been in contact with persons with confirmed swine flu, or who were in one of the five U.S. states that have reported swine flu cases or in Mexico during the 7 days preceding their illness onset."^[68] A diagnosis of confirmed swine flu requires laboratory testing of a respiratory sample (a simple nose and throat swab).^[68]

The most common cause of death is respiratory failure, other causes of death are pneumonia (leading to sepsis)^[69], high fever (leading to neurological problems), dehydration (from excessive vomiting and diarrhea) and electrolyte imbalance. Fatalities are more likely in young children and the elderly.

Prevention

Prevention of swine influenza has three components: prevention in swine, prevention of transmission to humans, and prevention of its spread among humans.

Prevention in swine

Methods of preventing the spread of influenza among swine include facility management, herd management, and vaccination (ATCvet code: QI09AA03). Because much of the illness and death associated with swine flu involves secondary infection by other pathogens, control strategies that rely on vaccination may be insufficient.

Control of swine influenza by vaccination has become more difficult in recent decades, as the evolution of the virus has resulted in inconsistent responses to traditional vaccines. Standard commercial swine flu vaccines are effective in controlling the infection when the virus strains match enough to have significant cross-protection, and custom (autogenous) vaccines made from the specific viruses isolated are created and used in the more difficult cases.^[70][71] Present vaccination strategies for SIV control and prevention in swine farms typically include the use of one of several bivalent SIV vaccines commercially available in the United States. Of the 97 recent H3N2 isolates examined, only 41 isolates had strong serologic cross-reactions with antiserum to three commercial SIV vaccines. Since the protective ability of influenza vaccines depends primarily on the closeness of the match between the vaccine virus and the epidemic virus, the presence of nonreactive H3N2 SIV variants suggests that current commercial vaccines might not effectively protect pigs from infection with a majority of H3N2 viruses.^[72][73] The United States Department of Agriculture researchers say that while pig vaccination keeps pigs from getting sick, it does not block infection or shedding of the virus.^[74]

Facility management includes using disinfectants and ambient temperature to control virus in the environment. The virus is unlikely to survive outside living cells for more than two weeks, except in cold (but above freezing) conditions, and it is readily inactivated by disinfectants.^[2] Herd management includes not adding pigs carrying influenza to herds that have not been exposed to the virus. The virus survives in healthy carrier pigs for up to 3 months and can be recovered from them between outbreaks. Carrier pigs are usually responsible for the introduction of SIV into previously uninfected herds and countries, so new animals should be quarantined.^[51] After an outbreak, as immunity in exposed pigs wanes, new outbreaks of the same strain can occur.^[2]