Health, as defined by the World Health Organization (WHO), is "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity." This definition has been subject to controversy, as it may have limited value for implementation. Health may be defined as the ability to adapt and manage physical, mental and social challenges throughout life.
Selected general articles
occurs when a person exceeds their body's ability to recover from strenuous exercise
. Overtraining can be described as a point where a person may have a decrease in performance and plateauing as a result of failure to consistently perform at a certain level or training load; a load which exceeds their recovery capacity. People who are overtrained cease making progress, and can even begin to lose strength
. Overtraining is also known as chronic fatigue, burnout and overstress in athletes. It is suggested that there are different variations of overtraining, firstly monotonous program over training suggest that repetition of the same movement such as certain weight lifting and baseball batting can cause performance plateau due to an adaption of the central nervous system which results from a lack of stimulation. A second example of overtraining is described as chronic overwork type training where the subject may be training with too high intensity or high volume and not allowing sufficient recovery time for the body. Up to 10% of elite endurance athletes and 10% of American college swimmers are affected by overtraining syndrome (unexplained underperformance for approximately 2 weeks even after having adequate resting time). Read more...
(alternatively preventive medicine, preventative healthcare/medicine,
) consists of measures taken for disease prevention, as opposed to disease treatment. Just as health
comprises a variety of physical and mental states, so do disease and disability, which are affected by environmental factors
, genetic predisposition
, disease agents, and lifestyle choices. Health, disease, and disability are dynamic processes which begin before individuals realize they are affected. Disease prevention relies on anticipatory actions that can be categorized as primal, primary, secondary, and tertiary prevention.
Each year, millions of people die of preventable deaths. A 2004 study showed that about half of all deaths in the United States in 2000 were due to preventable behaviors and exposures. Leading causes included cardiovascular disease
, chronic respiratory disease
, unintentional injuries, diabetes
, and certain infectious diseases. This same study estimates that 400,000 people die each year in the United States due to poor diet and a sedentary lifestyle
. According to estimates made by the World Health Organization
(WHO), about 55 million people died worldwide in 2011, two thirds of this group from non-communicable diseases, including cancer
, and chronic cardiovascular
and lung diseases
. This is an increase from the year 2000, during which 60% of deaths were attributed to these diseases. Preventive healthcare is especially important given the worldwide rise in prevalence of chronic diseases and deaths from these diseases.
There are many methods for prevention of disease. It is recommended that adults and children aim to visit their doctor for regular check-ups, even if they feel healthy, to perform disease screening
, identify risk factors for disease, discuss tips for a healthy and balanced lifestyle, stay up to date with immunizations and boosters, and maintain a good relationship with a healthcare provider. Some common disease screenings include checking for hypertension
(high blood pressure), hyperglycemia
(high blood sugar, a risk factor for diabetes mellitus
(high blood cholesterol), screening for colon cancer
and other common types of sexually transmitted disease
such as chlamydia
, and gonorrhea
(to screen for breast cancer
), colorectal cancer
screening, a Pap test
(to check for cervical cancer
), and screening for osteoporosis
. Genetic testing can also be performed to screen for mutations that cause genetic disorders
or predisposition to certain diseases such as breast or ovarian cancer
. However, these measures are not affordable for every individual and the cost effectiveness of preventive healthcare is still a topic of debate. Read more...
is the study and analysis of the distribution (who, when, and where) and determinants
of health and disease conditions in defined populations
It is the 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.
Major areas of epidemiological study include disease causation, transmission
investigation, disease surveillance
, environmental epidemiology
, forensic epidemiology
, occupational epidemiology
, and comparisons of treatment effects such as in clinical trials
. Epidemiologists rely on other scientific disciplines like biology
to better understand disease processes, statistics
to make efficient use of the data and draw appropriate conclusions, social sciences
to better understand proximate and distal causes, and engineering
for exposure assessment
. Read more...
Health gap in England and Wales, 2011 Census
refers to the study and causes of differences in the quality of health
across different populations. Health equity is different from health equality, as it refers only to the absence of disparities in controllable or remediable aspects of health. It is not possible to work towards complete equality in health, as there are some factors of health that are beyond human influence. Inequity implies some kind of social injustice. Thus, if one population dies younger than another because of genetic differences, a non-remediable/controllable factor, we tend to say that there is a health inequality. On the other hand, if a population has a lower life expectancy due to lack of access to medications, the situation would be classified as a health inequity. These inequities may include differences in the "presence of disease, health outcomes, or access to health care" between populations with a different race
, sexual orientation
Health equity falls into two major categories: horizontal equity, the equal treatment of individuals or groups in the same circumstances; and vertical equity, the principle that individuals who are unequal should be treated differently according to their level of need. Disparities in the quality of health across populations are well-documented globally in both developed and developing nations. The importance of equitable access to healthcare has been cited as crucial to achieving many of the Millennium Development Goals
. Read more...
A bottle of B-complex vitamin pills
is a organic molecule
(or related set of molecules) that is an essential micronutrient
that an organism
needs in small quantities for the proper functioning of its metabolism
. Essential nutrients cannot be synthesized
in the organism, either at all or not in sufficient quantities, and therefore must be obtained through the diet
. Vitamin C
can be synthesized by some species but not by others; it is not a vitamin in the first instance but is in the second. The term vitamin
does not include the three other groups of essential nutrients
, essential fatty acids
, and essential amino acids
. Most vitamins are not single molecules, but groups of related molecules called vitamers
. For example, vitamin E
consists of four tocopherols
and four tocotrienols
. The thirteen vitamins required by human metabolism are: vitamin A
-retinyl-esters, as well as all-trans
and other provitamin A carotenoids), vitamin B1
), vitamin B2
), vitamin B3
), vitamin B5
), vitamin B6
), vitamin B7
), vitamin B9
), vitamin B12
), vitamin C (ascorbic acid
), vitamin D
), vitamin E (tocopherols
), and vitamin K (quinones
Vitamins have diverse biochemical functions. Vitamin A acts as a regulator of cell and tissue growth and differentiation. Vitamin D provides a hormone-like function, regulating mineral metabolism for bones and other organs. The B complex
vitamins function as enzyme cofactors
(coenzymes) or the precursors
for them. Vitamins C and E function as antioxidants
. Both deficient and excess intake of a vitamin can potentially cause clinically significant illness, although excess intake of water-soluble vitamins is less likely to do so.
Before 1935, the only source of vitamins was from food. If intake of vitamins was lacking, the result was vitamin deficiency and consequent deficiency diseases. Then, commercially produced tablets of yeast-extract vitamin B complex and semi-synthetic vitamin C became available. This was followed in the 1950s by the mass production and marketing of vitamin supplements
, including multivitamins
, to prevent vitamin deficiencies in the general population. Governments mandated addition of vitamins to staple foods
such as flour or milk, referred to as food fortification
, to prevent deficiencies. Recommendations for folic acid
supplementation during pregnancy
reduced risk of infant neural tube defects
. Although reducing incidence of vitamin deficiencies clearly has benefits, supplementation is thought to be of little value for healthy people who are consuming a vitamin-adequate diet. Read more...
(from Greek καρδίᾱ kardiā
, "heart" and -λογία -logia
, "study") is a branch of medicine
that deals with the disorders of the heart
as well as some parts of the circulatory system
. The field includes medical diagnosis
and treatment of congenital heart defects
, coronary artery disease
, heart failure
, valvular heart disease
who specialize in this field of medicine are called cardiologists
, a specialty of internal medicine
. Pediatric cardiologists are pediatricians
who specialize in cardiology. Physicians who specialize in cardiac surgery are called cardiothoracic surgeons
or cardiac surgeons
, a specialty of general surgery
Although the cardiovascular system is inextricably linked to blood, cardiology is relatively unconcerned with hematology
and its diseases. Some obvious exceptions that affect the function of the heart would be blood tests (electrolyte
), decreased oxygen carrying capacity (anemia
, hypovolemic shock
), and coagulopathies
. Read more...
A dietary supplement
is a manufactured product intended to supplement the diet when taken by mouth as a pill, capsule, tablet, or liquid. A supplement can provide nutrients
either extracted from food sources or synthetic, individually or in combination, in order to increase the quantity of their consumption. The class of nutrient compounds includes vitamins
, fatty acids
and amino acids
. Dietary supplements can also contain substances that have not been confirmed as being essential to life, but are marketed as having a beneficial biological effect, such as plant pigments
. Animals can also be a source of supplement ingredients, as for example collagen
from chickens or fish. These are also sold individually and in combination, and may be combined with nutrient ingredients. In the United States and Canada, dietary supplements are considered a subset of foods, and are regulated accordingly. The European Commission
has also established harmonized rules to help insure that food supplements are safe and properly labeled.
Creating an industry estimated to have a 2015 value of $37 billion, there are more than 50,000 dietary supplement products marketed just in the United States, where about 50% of the American adult population consumes dietary supplements. Multivitamins
are the most commonly used product. For those who fail to consume a balanced diet, the United States National Institutes of Health
states that certain supplements "may have value."
In the United States, it is against federal regulations for supplement manufacturers to claim
that these products prevent or treat any disease. Companies are allowed to use what is referred to as "Structure/Function" wording if there is substantiation of scientific evidence for a supplement providing a potential health effect. An example would be "_____ helps maintain healthy joints", but the label must bear a disclaimer that the Food and Drug Administration
(FDA) "has not evaluated the claim and that the dietary supplement product is not intended to "diagnose, treat, cure or prevent any disease," because only a drug can legally make such a claim. The FDA enforces these regulations, and also prohibits the sale of supplements and supplement ingredients that are dangerous, or supplements not made according to standardized good manufacturing practices
(GMPs). Read more...
is a medical specialty that uses operative manual and instrumental techniques on a patient to investigate or treat a pathological condition such as a disease or injury, to help improve bodily function or appearance or to repair unwanted ruptured areas.
The act of performing surgery may be called a "surgical procedure", "operation", or simply "surgery". In this context, the verb "operate" means to perform surgery. The adjective "surgical" means pertaining to surgery; e.g. surgical instruments
or surgical nurse
. The patient or subject on which the surgery is performed can be a person or an animal. A surgeon
is a person who practices surgery and a surgeon's assistant
is a person who practices surgical assistance. A surgical team
is made up of surgeon, surgeon's assistant
provider, circulating nurse and surgical technologist
. Surgery usually spans minutes to hours, but it is typically not an ongoing or periodic type of treatment. The term "surgery" can also refer to the place where surgery is performed, or, in British English, simply the office of a physician
, or veterinarian
. Read more...
, also known as Dental and Oral Medicine
, is a branch of medicine
that consists of the study, diagnosis
, prevention, and treatment of diseases
, disorders, and conditions of the oral cavity
, commonly in the dentition
but also the oral mucosa
, and of adjacent and related structures and tissues, particularly in the maxillofacial (jaw and facial) area. Although primarily associated with teeth
among the general public, the field of dentistry or dental medicine is not limited to teeth but includes other aspects of the craniofacial
complex including the temporomandibular joint
and other supporting, muscular, lymphatic, nervous, vascular, and anatomical structures.
Dentistry is often also understood to subsume the now largely defunct medical specialty
(the study of the mouth and its disorders and diseases) for which reason the two terms are used interchangeably in certain regions.
Dental treatments are carried out by a dental team, which often consists of a dentist
and dental auxiliaries
, dental hygienists
, dental technicians
, as well as dental therapists
). Most dentists either work in private practices (primary care
), dental hospitals or (secondary care
) institutions (prisons, armed forces bases, etc.). Read more...
The structure of an alpha amino acid in its un-ionized form
are organic compounds
) and carboxyl
(-COOH) functional groups
, along with a side chain
(R group) specific to each amino acid. The key elements
of an amino acid are carbon
(O), and nitrogen
(N), although other elements are found in the side chains of certain amino acids. About 500 naturally occurring amino acids are known (though only 20 appear in the genetic code
) and can be classified in many ways. They can be classified according to the core structural functional groups' locations as alpha- (α-), beta- (β-), gamma- (γ-) or delta- (δ-)
amino acids; other categories relate to polarity
level, and side chain group type (aliphatic
, containing hydroxyl
, etc.). In the form of proteins
, amino acid residues
form the second-largest component (water
is the largest) of human muscles
and other tissues
. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter
transport and biosynthesis
, amino acids having both the amine and the carboxylic acid groups attached to the first (alpha-) carbon
atom have particular importance. They are known as 2-, alpha-,
or α-amino acids
NCHRCOOH in most cases, where R is an organic substituent
known as a "side chain
"); often the term "amino acid" is used to refer specifically to these. They include the 22 proteinogenic
("protein-building") amino acids, which combine into peptide
chains ("polypeptides") to form the building-blocks of a vast array of proteins
. These are all L
), although a few D
-amino acids ("right-handed") occur in bacterial envelopes
, as a neuromodulator
), and in some antibiotics
Twenty of the proteinogenic amino acids are encoded directly by triplet codons
in the genetic code
and are known as "standard" amino acids. The other two ("non-standard" or "non-canonical") are selenocysteine
(present in many prokaryotes
as well as most eukaryotes
, but not coded directly by DNA
), and pyrrolysine
(found only in some archea
and one bacterium
). Pyrrolysine and selenocysteine are encoded via variant codons; for example, selenocysteine is encoded by stop codon
and SECIS element
(which is often the initial amino acid of proteins in bacteria, mitochondria
, and chloroplasts
) is generally considered as a form of methionine
rather than as a separate proteinogenic amino acid. Codon–tRNA
combinations not found in nature can also be used to "expand" the genetic code
and form novel proteins known as alloproteins
incorporating non-proteinogenic amino acids
. Read more...
Proper oral hygiene requires regular brushing and flossing
is the practice of keeping one's mouth clean and free of disease
and other problems (e.g. bad breath
) by regular brushing of the teeth (dental hygiene
) and cleaning between the teeth. It is important that oral hygiene be carried out on a regular basis to enable prevention of dental disease and bad breath
. The most common types of dental disease are tooth decay
, dental caries
) and gum diseases, including gingivitis
, and periodontitis
General guidelines suggest brushing twice a day: after breakfast and before going to bed, but ideally the mouth would be cleaned after every meal. Cleaning between the teeth is called interdental cleaning
and is as important as tooth brushing
. This is because a toothbrush cannot reach between the teeth and therefore only removes about 50% of plaque off the surface. There are many tools to clean between the teeth, including floss, flossettes, and interdental brushes; it is up to each individual to choose which tool he or she prefers to use.
Sometimes white or straight teeth are associated with oral hygiene, but a hygienic mouth may have stained teeth and/or crooked teeth. For appearance reasons, people may seek out teeth whitening
. Read more...
In the context of nutrition, a mineral
is a chemical element
required as an essential nutrient
to perform functions necessary for life. However, the four major structural elements in the human body by weight (oxygen, hydrogen, carbon, and nitrogen), are usually not included in lists of major nutrient minerals (nitrogen is considered a "mineral" for plants, as it often is included in fertilizers). These four elements compose about 96% of the weight of the human body, and major minerals (macrominerals) and minor minerals (also called trace elements) compose the remainder.
Minerals, as elements, cannot be synthesized biochemically by living organisms. Plants get minerals from soil
. Most of the minerals in a human diet come from eating plants and animals or from drinking water. As a group, minerals
are one of the four groups of essential nutrients, the others of which are vitamins
, essential fatty acids
, and essential amino acids
. The five major minerals in the human body
, and magnesium
. All of the remaining elements in a human body are called "trace elements". The trace elements that have a specific biochemical function in the human body are sulfur
Most chemical elements
that are ingested
by organisms are in the form of simple compounds. Plants absorb dissolved elements in soils, which are subsequently ingested by the herbivores
that eat them, and the elements move up the food chain
. Larger organisms may also consume soil (geophagia
) or use mineral resources, such as salt licks
, to obtain limited minerals unavailable through other dietary sources. Read more...
, caloric restriction
, or energy restriction
, is a dietary regimen
that reduces calorie
intake without incurring malnutrition
or a reduction in essential nutrients
. "Reduce" can be defined relative to the subject's previous intake before intentionally restricting calories, or relative to an average person of similar body type. Commonly consumed food components containing calories are carbohydrates
In preliminary research, some non-human species on calorie restriction diets without malnutrition may exhibit slowing of the biological aging process
, resulting in an increase in both median
and maximum lifespan
, but this effect is not universal. In humans, the long-term health effects of moderate caloric restriction with sufficient nutrients are unknown. Read more...
, also spelled haematology
, is the branch of medicine
concerned with the study of the cause, prognosis, treatment, and prevention of diseases related to blood
. It involves treating diseases that affect the production of blood and its components, such as blood cells
, blood proteins
, bone marrow
, blood vessels
, and the mechanism of coagulation
. Such diseases might include hemophilia
, blood clots, other bleeding disorders and blood cancers
such as leukemia
, multiple myeloma
, and lymphoma
. The laboratory work that goes into the study of blood is frequently performed by a medical technologist
or medical laboratory scientist
. Read more...
Did you know...
- ... that Rudolf Geigy established health institutes on two continents and started a foundation that awards scholars who combine field and laboratory work in novel ways?
- ... that a collaborative practice agreement, which allows a pharmacist to prescribe medications, order drug therapy-related laboratory tests, and design therapy plans, can improve people's health?
- ... that the orange cup coral obtains part of its nutritional needs from carbon compounds dissolved in sea water?
- ... that Luke Fildes' painting The Doctor was used to promote state-run healthcare in Britain and to campaign against it in the United States?
- ... that Melahat Okuyan, a Turkish female microbiologist and AIDS activist, once proposed the establishment of male brothels for homosexuals and cross-dressers in order to improve public health?
- ... that following her diagnosis of terminal lung cancer, the British Vogue health editor Deborah Hutton campaigned to raise awareness of the dangers of smoking for teenage girls?
Do you have a question about Health that you can't find the answer to?
Consider asking it at the Wikipedia reference desk.
For editor resources and to collaborate with other editors on improving Wikipedia's Health-related articles, see WikiProject Health.
Postage stamp, New Zealand, 1933. Public health has been promoted – and depicted – in a wide variety of ways.
Percentage of overweight or obese population in 2010, Data source: OECD's iLibrary.
Colorful fruits and vegetables may be components of a healthy diet.
A woman jogging at a beach in the U.S. to maintain/improve her physical fitness
Running has become a popular form of exercise.
Jack Drummond’s single-paragraph article in 1920 which provided structure and nomenclature used today for vitamins
James Lind conducted in 1747 the first controlled clinical trial in modern times, and in 1753 published Treatise on Scurvy.
Summary of long-term adaptations to regular aerobic and anaerobic exercise. Aerobic exercise can cause several central cardiovascular adaptations, including an increase in stroke volume (SV) and maximal aerobic capacity (VO2 max), as well as a decrease in resting heart rate (RHR). Long-term adaptations to resistance training, the most common form of anaerobic exercise, include muscular hypertrophy, an increase in the physiological cross-sectional area (PCSA) of muscle(s), and an increase in neural drive, both of which lead to increased muscular strength. Neural adaptations begin more quickly and plateau prior to the hypertrophic response.
Swimmers perform squats prior to entering the pool in a U.S. military base, 2011.
Followed for a millennium and a half, Galen (1st century) created the first coherent (although mistaken) theory of nutrition.
A bottle of B-complex vitamin pills
Proteins are chains of amino acids found in most nutritional foods.
A lady washing her hands c. 1655
Percentage of obese population in 2010, Data source: OECD's iLibrary.
Roper's gymnasium, Philadelphia, circa 1831.
Hippocrates lived about 400 BC, and Galen and the understanding of nutrition followed him for centuries.
Calcium combined with vitamin D (as calciferol) supplement tablets with fillers.
An astronaut, Daniel Tani, working out with a short bar to increase his upper body strength while in a microgravity environment
In the news
- 30 March 2019 – 2018 Gaza border protests, Gaza–Israel conflict
- On the one year anniversary of the Gaza border protests, tens of thousands of Palestinians gather on the border to commemorate the weekly gatherings. Four Palestinian protesters have been killed and more than 300 wounded according to Palestinian health officials. (BBC) (Sky News)
- 24 March 2019 – Stoneman Douglas High School massacre aftermath
- More than 60 school, county, city, child services and law enforcement officials, as well as mental health specialists, teachers and parents, hold an emergency meeting after the suicide of a second Stoneman Douglas survivor. Florida's emergency chief is requesting the state Legislature provide more mental health resources for the community. Coral Springs, Florida, police reported that, Saturday night, a current sophomore killed himself. Last week, Sydney Aiello, a 19-year-old graduate who had recently been diagnosed with post-traumatic stress disorder, took her own life. (The Guardian) (Miami Herald)
- See also: Biology (below)
Health – Health is a state of complete physical, mental and social well-being. this is a level of functional and (or) metabolic efficiency of a person in mind, body and spirit; being free from illness, injury or pain (as in “good health” or “healthy”). The World Health Organization (WHO) defined health in its broader sense in 1946 as "a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity."
- Death – cessation of life.
- Exercise – any bodily activity that enhances or maintains physical fitness and overall health and wellness. It is performed for various reasons including strengthening muscles and the cardiovascular system, honing athletic skills, weight loss or maintenance, and mental health including the prevention of depression. Frequent and regular physical exercise boosts the immune system, and helps prevent the "diseases of affluence" such as heart disease, cardiovascular disease, Type 2 diabetes mellitus and obesity.
- Nutrition – provision, to cells and organisms, of the materials necessary (in the form of food) to support life.
- Life extension – The study of slowing down or reversing the processes of aging to extend both the maximum and average lifespan.
- Health sciences – applied sciences that address the use of science, technology, engineering or mathematics in the delivery of healthcare to human beings.
- Medicine – science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness.
- Anesthesia – a way to control pain during a surgery or procedure by using medicine called anesthetics.
- Cardiology – branch of medicine dealing with disorders of the human heart. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology.
- Clinical research – aspect of biomedical research that addresses the assessment of new pharmaceutical and biological drugs, medical devices and vaccines in humans.
- Diabetes – a group of metabolic diseases in which the person has high blood glucose (blood sugar) above 200mg/dl, either because insulin production is inadequate, or because the body's cells do not respond properly to insulin, or both.
- Dentistry – branch of medicine that is involved in the study, diagnosis, prevention, and treatment of diseases, disorders and conditions of the mouth, maxillofacial area and the adjacent and associated structures (teeth) and their impact on the human body.
- Emergency medicine – medical specialty involving care for undifferentiated, unscheduled patients with acute illnesses or injuries that require immediate medical attention. Emergency physicians undertake acute investigations and interventions to resuscitate and stabilize patients.
- Obstetrics – medical specialty dealing with the care of all women's reproductive tracts and their children during pregnancy (prenatal period), childbirth and the postnatal period.
- Trauma and Orthopedics – medical specialty dealing with bones, joints and operative management of trauma.
- Psychiatry – medical specialty devoted to the study and treatment of mental disorders. These mental disorders include various affective, behavioural, cognitive and perceptual abnormalities.
- Autism a mental condition, present from early childhood, characterized by great difficulty in communicating and forming relationships with other people and in using language and abstract concepts.
- Bipolar disorder – mental disorder that causes periods of depression and periods of abnormally elevated mood.
- Psychiatric survivors movement – is a diverse association of individuals who either currently access mental health services (known as consumers or service users), or who are survivors of interventions by psychiatry, or who are ex-patients of mental health.