Rheumatology (Greek ῥεῦμα, rheûma, flowing
current) is a branch of medicine devoted to the diagnosis and management
of disorders whose common feature is inflammation in the bones,
muscles, joints, and internal organs. Rheumatology covers more than 100 different complex diseases, collectively known as rheumatic diseases, which includes many forms of arthritis as well as lupus and Sjögren's syndrome. Doctors who have undergone formal training in rheumatology are called rheumatologists.
Many of these diseases are now known to be disorders of the immune system, and rheumatology has significant overlap with immunology, the branch of medicine that studies the immune system.
A rheumatologist is a physician
who specializes in the field of medical sub-specialty called
rheumatology. A rheumatologist holds a board certification after
specialized training. In the United States, training in this field
requires four years undergraduate school, four years of medical school,
and then three years of residency, followed by two or three years
additional Fellowship training. The requirements may vary in other
countries. Rheumatologists are internists
who are qualified by additional postgraduate training and experience in
the diagnosis and treatment of arthritis and other diseases of the
joints, muscles and bones. Many rheumatologists also conduct research to
determine the cause and better treatments for these disabling and
sometimes fatal diseases. Treatment modalities are based on scientific
research, currently, practice of rheumatology is largely evidence based.
Rheumatologists treat arthritis, autoimmune diseases, pain disorders affecting joints, and osteoporosis. There are more than 200 types of these diseases, including rheumatoid arthritis, osteoarthritis, gout, lupus, back pain, osteoporosis, and tendinitis.
Some of these are very serious diseases that can be difficult to
diagnose and treat. They treat soft tissue problems related to the
musculoskeletal system, and sports related soft tissue disorders.
Most rheumatic diseases are treated with analgesics, NSAIDs (nonsteroidal anti-inflammatory drug), steroids (in serious cases), DMARDs (disease-modifying antirheumatic drugs), monoclonal antibodies, such as infliximab and adalimumab, the TNF inhibitoretanercept, and methotrexate for moderate to severe rheumatoid arthritis. The biologic agent rituximab (anti-B cell therapy) is now licensed for use in refractory rheumatoid arthritis.
Physiotherapy is vital in the treatment of many rheumatological disorders. Occupational therapy
can help patients find alternative ways for common movements that would
otherwise be restricted by their disease. Patients with rheumatoid
arthritis often need a long term, coordinated and a multidisciplinary
team approach towards management of individual patients. Treatment is
often tailored according to the individual needs of each patient which
is also dependent on the response and the tolerability of medications.
Rheumasurgery (or rheumatoid surgery) is a subfield of orthopedics occupied with the surgical treatment of patients with rheumatic diseases. The purpose of the interventions is to limit disease activity, soothe pain and improve function.
Rheumasurgical interventions can be divided in two groups. The one is early synovectomies, that is the removal of the inflamed synovia
in order to prevent spreading and stop destruction. The other group is
the so-called corrective intervention, i.e. an intervention done after
destruction has taken place.
Among the corrective interventions are joint replacements, removal of
loose bone or cartilage fragments, and a variety of interventions aimed
at repositioning and/or stabilizing joints, such as arthrodesis.
Research directions
Recently, a large body of scientific research deals with the background of autoimmune disease, the cause of many rheumatic disorders. Also, the field of osteoimmunology
has emerged to further examine the interactions between the immune
system, joints, and bones. Epidemiological studies and medication trials
are also being conducted. The Rheumatology Research Foundation is the largest private funding source of rheumatology research and training in the United States.
History
Rheumasurgery emerged in the cooperation of rheumatologists and orthopedic surgeons in Heinola, Finland, during the 1950s.
In 1970 a Norwegian investigation estimated that at least 50% of
patients with rheumatic symptoms needed rheumasurgery as an integrated
part of their treatment.
Around the turn of the 21st century, focus for treatment of
patients with rheumatic disease shifted, and pharmacological treatment
became dominant, while surgical interventions became rarer.
Obesity may cause a number of medical complications which negatively impact peoples' quality of life.
Obesity is a risk factor for many chronic physical and mental illnesses.
The health effects of being overweight but not obese are
controversial, with some studies showing that the mortality rate for
individuals who are classified as overweight (BMI 25.0 to 29.9) may
actually be lower than for those with an ideal weight (BMI 18.5 to
24.9). Health risks for those who are overweight may be decreasing over time as a result of improvements in medical care.
Some obesity-associated medical conditions may be the result of stress
caused by medical discrimination against people who are obese, rather
than the direct effects of obesity, and some may be exacerbated by the
relatively poor healthcare received by people who are obese.
Because of the social stigma of obesity, people who are obese may receive poorer healthcare than people within the normal BMI weight range, potentially contributing to the relationship between obesity and poor health outcomes.
People who experience weight-related discrimination, irrespective of
their actual weight status, similarly have poorer health outcomes than
those who do not experience weight-related discrimination. People who are obese are also less likely to seek medical care than people who are not obese, even if the weight gain is caused by medical problems. Peter Muennig, a professor in the Department of Health Policy and Management at Columbia University,
has proposed that obesity-associated medical conditions may be caused
"not from adiposity alone, but also from the psychological stress
induced by the social stigma associated with being obese".
Body weight is not considered to be an independently predictive risk factor for cardiovascular disease by current (as of 2014) risk assessment tools. Mortality from cardiovascular disease has decreased despite increases in obesity,
and at least one clinical trial was stopped early because the weight
loss intervention being tested did not reduce cardiovascular disease.
Ischemic heart disease
Abdominal obesity is associated with cardiovascular diseases including angina and myocardial infarction.
However, overall obesity (as measured by BMI) may lead to false
diagnoses of myocardial infarction and may decrease mortality after
acute myocardial infarction.
In 2008, European guidelines concluded that 35% of ischemic heart disease among adults in Europe is due to obesity.
Congestive heart failure
Having obesity is associated to about 11% of heart failure cases in males and 14% in females.
High blood pressure
More than 85% of those with hypertension have a BMI greater than 25, although diet is probably a more important factor than body weight. Risk estimates indicate that at least two-thirds of people with hypertension can be directly attributed to obesity. The association between obesity and hypertension has been found in animal and clinical studies,
which have suggested that there are multiple potential mechanisms for
obesity-induced hypertension. These mechanisms include the activation of
the sympathetic nervous system as well as the activation of the renin–angiotensin–aldosterone system.
As of 2007, it was unclear whether there is an association between
hypertension and obesity in children, but there is little direct
evidence that blood pressure has increased despite increases in
pediatric overweight.
The link between obesity and type 2 diabetes is so strong that researchers in the 1970s started calling it "diabesity". Excess weight is behind 64% of cases of diabetes in males and 77% of cases in females.
Gynecomastia
In some individuals, obesity can be associated with elevated peripheral conversion of androgens into estrogens.
Several studies have shown that the frequency and severity of GERD symptoms increase with BMI, such that people who are underweight have the fewest GERD symptoms, and people who are severely obese have the most GERD symptoms. However, most studies find that GERD symptoms are not improved by nonsurgical weight loss.
Cholelithiasis (gallstones)
Obesity causes the amount of cholesterol in bile to rise, in turn the formation of stone can occur.
Due to its association with insulin resistance, the risk of obesity increases with polycystic ovarian syndrome
(PCOS). In the US approximately 60% of patients with PCOS have a BMI
greater than 30. It remains uncertain whether PCOS contributes to
obesity, or the reverse.
Infertility
Obesity can lead to infertility in both males and females. This is primarily due to excess estrogen interfering with normal ovulation in females and altering spermatogenesis in males. It is believed to cause 6% of primary infertility. A review in 2013 came to the result that obesity increases the risk of oligospermia and azoospermia in males, with an of odds ratio 1.3. Being morbidly obese increases the odds ratio to 2.0.
Complications of pregnancy
Obesity is related to many complications in pregnancy including: haemorrhage, infection, increased hospital stays for the mother, and increased NICU requirements for the infant. Obese females also have increased risk of preterm births and low birth weight infants.
Obese females have more than twice the rate of C-sections compared to females of "normal" weight. Some have suggested that this may be due in part to the social stigma of obesity.
Ischemic stroke is increased in both men and women who are obese.
Meralgia paresthetica
Meralgia paresthetica is a neuropathic pain or numbness of the thighs, sometimes associated with obesity.
Migraines
Migraine (and headaches in general) is comorbid with obesity. The risk of migraine rises 50% by BMI of 30 kg/m2 and 100% by BMI of 35 kg/m2. The causal connection remains unclear.
One review found that those who are obese do not have a significantly higher rate of dementia than those with "normal" weight.
Idiopathic intracranial hypertension
Idiopathic intracranial hypertension, or unexplained high pressure in the cranium, is a rare condition that can cause visual impairment, frequent severe headache, and tinnitus.
It is most commonly seen in obese women, and the incidence of
idiopathic intracranial hypertension is increasing along with increases
in the number of people who are obese.
Multiple sclerosis
Obese female individuals at 18 years of age have a greater than twofold increased risk of multiple sclerosis compared to females with a BMI between 18.5 and 20.9.
Female individuals who are underweight at age 18 have the lowest risk
of multiple sclerosis. However, body weight as an adult was not
associated with risk of multiple sclerosis.
Many cancers occur at increased frequency in those who are overweight
or obese. A study from the United Kingdom found that approximately 5%
of cancer is due to excess weight. These cancers include:
A high body mass index (BMI)
is associated with a higher risk of developing ten common cancers
including 41% of uterine cancers and at least 10% of gallbladder,
kidney, liver and colon cancers in the UK.
For those undergoing surgery for cancer, obesity is also associated
with an increased risk of major postoperative complications compared
with those of "normal" weight.
Obesity has been associated with depression, likely due to social factors rather than physical effects of obesity.
However, it is possible that obesity is caused by depression (due to
reduced physical activity or, in some people, increases in appetite). Obesity-related disabilities may also lead to depression in some people. Repeated failed attempts at weight loss might also lead to depression.
The association between obesity and depression is strongest in
those who are more severely obese, those who are younger, and in women. Suicide rate however decreases with increased BMI. Similarly, weight loss through bariatric surgery is associated with increased risk of suicide.
Obese people draw negative reactions from others, and people are less
willing to help obese individuals in any situation due to social
stigmatization. People who are obese also experience fewer educational and career opportunities, on average earn a lesser income, and generally receive poorer health care and treatment than individuals of "normal" weight.
Obesity is associated with a number of chronic lung diseases, including asthma and COPD.
It is believed that a systemic pro-inflammatory state induced by some
causes of obesity may contribute to airway inflammation, leading to
asthma.
Complications during general anaesthesia
Obesity
significantly reduces and stiffens the functional lung volume,
requiring specific strategies for respiratory management under general anesthesia.
Obesity and asthma
The
low grade systemic inflammation of obesity has been shown to worsen
lung function in asthma and increase the risk of developing an asthma
exacerbation.
COVID-19
A
study in England found a linear increase in severe COVID-19 resulting in
hospitalisation and death for those whose BMI is above 23, and a linear
increase in admission to an intensive care unit across the whole BMI
spectrum. The difference in COVID-19 risk from having a high BMI was
most pronounced in people aged under 40, or who were black.
A study from Mexico found that obesity alone was responsible for a 2.7
times increased risk of death from COVID-19, while comorbidities with
diabetes, immunosuppression or high blood pressure increased the risk
further.
A study from the United States found that there was an inverse
correlation between age and BMI of COVID patients; the younger the age
group, the higher its BMI.
Compared to men with a BMI of 21–22.9, men with a BMI of 30–34.9 have 2.33 times more gout, and men with a BMI ≥ 35 have 2.97 times more gout. Weight loss decreases these risks.
Poor mobility
There is a strong association between obesity and musculoskeletal pain and disability.
Osteoarthritis
Increased rates of arthritis are seen in both weight-bearing and non-weight-bearing joints. Weight loss and exercise act to reduce the risk of osteoarthritis.
Low back pain
Obese individuals are twice to four times more likely to have lower back pain than their "normal" weight peers.
Traumatic injury
In females, low BMI is a risk factor for osteoporotic fractures in general. In contrast, obesity is a protective factor for most osteoporotic fractures.
Urge, stress, and mixed incontinence all occur at higher rates in obese people. The rates of urinary incontinence are about double that found in the "normal" weight population. Urinary incontinence improves with weight loss.
Body positivity is a social movement
focused on the acceptance of all bodies, regardless of size, shape,
skin tone, gender, and physical abilities, while challenging present-day
beauty standards as an undesirable social construct. Proponents focus on the appreciation of the functionality and health of the human body, instead of its physiological appearance.
This is similar to the concept of body neutrality, that focuses on a similar concept.
Viewpoints
Body-positive advocates believe that size, like race, gender, sexuality, and physical capability, is one of the many ways that our bodies are placed in a power and desirability hierarchy.
In other words, judgments about one's physical appearance inherently
place one on a certain rung of a ladder that rates and values one's
desirability, effectively increasing or reducing one's power in society.
The movement aims to challenge unrealistic ideals of physical attractiveness, build positive body image, and improve self-confidence. A central belief advocated is that beauty is a construct of society and that this construct should not determine one's confidence or self-worth. Individuals are encouraged to love themselves to the fullest while not only accepting but even embracing their physical traits.
Body positivity has roots in the fat acceptance movement as well as the National Association to Advance Fat Acceptance. Body positivity differs from fat acceptance in that it is all encompassing and inclusive of all body types, whereas fat acceptance only advocates for individuals considered to be obese or overweight. The movement argues that neither fat-shaming nor skinny-shaming is acceptable, and that all body types can and should be celebrated.
Although body positivity is perceived as the celebration of one's physical appearance as it is, women are highly motivated to advocate the normalization of body hair, bodily fluids, menstruation, and to challenge preconceived ideas regarding a woman's appearance.
As part of the first wave of feminism from the 1850s-1890s, the Victorian Dress Reform Movement aimed to put an end to the trend of women having to modify their bodies through use of corsets and tightlacing in order to fit the societal standard of tiny waistlines.
A minority of women participated in this tradition of conformity, but
often ended up facing ridicule whether or not they were successful at
shrinking their waistline. The practice of tight-lacing proved to have
many negative health risks, and was also extremely uncomfortable for
women who partook. Women were mocked for their egotism if they were not
able to shrink their waistline, and they were criticized for too small a
waistline if they were successful. This instilled a feeling of defeat
in women during these times, as nothing they did seemed to satisfy their
male counterparts. As part of the Victorian Dress Reform Movement,
women also fought for their right to dress in pants.
Acceptance of all body types – regardless of waist measurements – was
the major theme of the Victorian Dress Reform Movement, and this was the
first movement of its kind.
First wave (1960s)
The origins of the body positivity movement date back to the Fat Acceptance movement
of the 1960s. The idea of ending fat-shaming served as the seed of a
larger project of accepting and celebrating all bodies and body types.
In 1967, New York radio host Steve Post
held a "fat-in" in Central Park. This event involved a group of people
who were partaking while holding posters of a famous thin woman and
setting diet books on fire. He described the purpose of the event "was to protest discrimination against the fat." This moment is often cited as the beginning of the Fat Acceptance movement.
Five months after the "fat-in", Lew Louderback composed an essay
entitled "More People Should be Fat!" as a result of him witnessing the
discrimination his wife experienced for her size.
The essay shed light on the discrimination fat people experience in
America and the culture surrounding fat-shaming. Louderback's
contribution inspired the creation of the National Association to Advance Fat Acceptance (NAAFA) in 1969 by Bill Fabrey, with the mission of ending discrimination based on body weight.
Second wave (1990s)
The
second wave of the body positivity movement prioritized providing
people of all sizes a place where they could comfortably come together
and exercise. There were programs being made specifically for overweight
people, such as Making Waves. Home exercise programs like Genia Pauli Haddon and Linda DeMarco's home exercise video series Yoga For Round Bodies were also made for those who were not comfortable joining a wellness community.
During the 90's, dangers in dieting were found, mostly saying that it
was ineffective and caused more physical and psychological problems, and
did not actually solve anything. Therefore, people sought help from
dieting. They wanted to learn how to eat again. Chronic dieting had not
proven to be effective. Dieting had been used as a ploy to get people's
money and proven to not actually work, especially in the long term.
Third wave (2010s)
The
third wave of the body positivity movement arose around 2012 largely as
a response to the increase in social media culture and advertisements. The rise of Instagram
inspired a debate about cultural beauty standards, and the body
positivity movement arose as a response and argument in favor of
embracing all body types, loving, and feeling confident about one's own
body even with any flaws.
Since 2012, there has been a heightened presence of the movement,
although corporations have capitalized on the sentiments in order to
sell products.
The movement challenged ideals including unblemished skin and slim "beach bodies". Model and feminist Tess Holliday
founded '@EffYourBeautyStandards', which brought an outpour of support
to the body positivity movement. After founding the movement, the
size-26 Holliday was signed to Milk Management, a large model agency in
Europe, as their first model over size 20. Instagram
has been utilized as an advertising platform for the movement since.
Pioneers connect with brands and advertisers to promote the movement. In 2016, Mattel released a new line of Barbie dolls under the name Fashionistas with three different body shapes, seven skin colors, twenty-two eye colors and twenty-four hairstyles to be more inclusive.
Additionally, in the spring 2019 New York Fashion Week, a total of 49
models that were considered plus-size made an appearance in 12 shows.
These plus-size models were also hired to be featured on fashion
campaigns as well as magazine covers.
Psychology
The
body positivity movement aims to change societal and individual
perceptions of weight, size, and appearance to be more accepting of all
bodies regardless of their diverse characteristics. An individual's perception of their body can greatly influence their mental health and overall well-being, particularly in teenagers.
Poor body image, also known as body dissatisfaction, has been linked to
a range of physical and mental health problems including anorexia, bulimia, depression, body image disturbance, and body dysmorphic disorder. Partakers are encouraged to view self-acceptance and self-love as traits that dignify the person.
The movement advocates against determining self-worth based on physical appearance or perceptions of one's own beauty. In the field of psychology,
this is referred to as appearance-contingent self-worth, and can be
highly detrimental to an individual's mental health. The degree to which
one feels proud of their physical appearance is referred to as
appearance self-esteem. People who fall under the appearance-contingent
self-worth umbrella put great effort into looking their best so that
they feel their best. This is can be beneficial when an individual feels
that they look good, but is extremely negative and anxiety-inducing
when they do not.
Inclusion
The
body positivity movement focuses largely on women, recognizing that
women face more societal pressure to conform to beauty standards than
men. Eating disorders are more common in women due to this social phenomenon. Nevertheless, men may face societal pressures to fit into a masculine physical ideal. Qualities that fit that mold are height, rectus abdominis muscle or "six pack abs", a broad upper body, muscular arms, shoulders, pectoral muscles, genital shape and size, etc. Men may face anxiety and pressure to shape their bodies to fit this mold and may struggle with body image disorders, including body dysmorphia, anorexia nervosa and bulimia nervosa. Eating disorders in men are less commonly diagnosed and therefore less publicized. Although there is an underdiagnosis of body dysmorphic disorder, the clinical symptoms can affect people of any gender.
While body positivity has largely been discussed with regard to women,
the body positivity movement may uplift people of all genders and sexes -
as well as ages, races, ethnicities, sexual preferences, and religions.
Brand influence and social media
Due
to social media the notion "every body is beautiful" came into being.
The movement for body positivity has played a role in influencing marketing campaigns for major corporations. In 2004, Dove launched their "Real Beauty" campaign, in which advertisements depicted women of varying body types and skin tones in a manner that portrayed acceptance and positivity towards their bodies. On their website, Dove presents its Dove Self-Esteem Project
as a mission for "helping young people reach their full potential by
delivering quality body confidence and self-esteem education". The company also partners with and raises money for eating disorder organizations.
In 2017, the American women's underwear company Aerie launched a campaign called "AerieReal", in which the company promised to not retouch or edit their models, encouraging body positivity and body-acceptance despite features such as cellulite, stretch marks, or fat rolls. Aerie has begun featuring body positive influencers in their photo shoots and advertising campaigns, as well as plus sized models. To accommodate the last, the brand has launched a plus size clothing line.
In 2019, Decathlon joined the efforts of other companies with their #LeggingsForEverybody campaign, stating their mission as "to boost body confidence and support you in your fitness journey".
Recently, paradigms on social media have been changing from pushing feminine beauty ideals to challenging those ideals through image related empowerment and inspiration. Several influencers such as AerieReal model Iskra Lawrence have been preaching body positivity, creating hashtags such as #IWokeUpLikeThis, #EffYourBeautyStandards, #HonorMyCurves, #CelebrateMySize, #GoldenConfidence, and #ImNoModelEither.
Social media plays a pivotal role in the body positivity
movement, in part by providing education and exposure on different body
types. Instagram and Facebook
are some social platforms that, as of 2019, have body positive policies
that cause advertisements for cosmetic surgery, weight loss
supplements, and detox products, to be hidden from underaged
demographics. In addition to promoting positive body image, these policies aim to curb the advertisement of supplements unregulated by the Food and Drug Administration (FDA). Social media platforms such as Instagram are frequently used to post body positivity content and fuel related discussion.
Although studies about social media and body image are still in
their early stages, there seems to be a correlation between social media
use and body image concerns. Body image tends to be positively or
negatively affected by the content to which people are exposed on social
media. The action of people uploading pictures of themselves appears to
effectuate a negative body image.
The body positivity movement has been criticized for encouraging
lifestyle habits that negatively affect one's health. A central
complaint is that excessive approval of overweight and obese individuals
could dissuade them from desiring to improve their health, leading to lifestyle disease. Among health professionals, agreement with the movement is very low. A 2012 study found that among a sample of 1,130 trainee dietitians, nutritionists, nurses and medical doctors, only 1.4% had "positive or neutral attitudes" regarding excess body fat.
The movement has also faced criticism from feminists. Gender scholar Amber E. Kinser
wrote that posting an unedited photo of your body to a social media
website, which is an example of an action associated with the movement,
does little to prevent women's worth from being directly correlated to
their physical appearance.
With the majority of the body positivity movement recently
occurring on Instagram, a recent study found that 40 percent of body
positivity posts were centered around appearance.
With Instagram being a photo-sharing social media site, the effort to
place the focus less on appearance has been criticized to be
contradictory.
Another criticism is that the movement puts too much emphasis on
the role of the individual to improve their own body image, and not
enough attention on identifying and eliminating the cultural forces,
messages, beliefs, and advertising campaigns accountable for causing
widespread body dissatisfaction.
The criticism has also been leveled that the movement can impair
one's agency and authenticity. Researcher Lisa Legault argues that an
undue emphasis on body positivity can "stifle and diminish important
negative feelings." She explains that negative feelings are a natural
part of the human experience and that such feelings can be important and
informational. She says "ignoring negative feelings and experiences
exerts a cost to authenticity and self-integration." The movement,
Legault argues, cannot make it seem like a person should only feel
positive emotions. This expectation to have only positive feelings is
sometimes called "toxic body positivity."
Positive effects of body positivity
Understanding
the positive impacts of body positivity has allowed society to embrace
new ways of thinking about the self and individual bodies. According to
Chef Sky Hanka, there are different ways to love your body but also
ditch negativity. The idea of body positivity can result in individuals
feeling more optimistic about their bodies, which can lead to improved
self-esteem and overall self-confidence. Embracing body positivity
starts with thoughts, words, and actions. Individuals spend the most
time with themself, so they must not break their relationship with
themselves.
When embracing body positivity, a person should not beat themself up if
there are moments when they are struggling with their body image.
Working with body positivity, step by step – will eventually improve
one’s self-esteem.
A healthy person often has a relationship with their body.
Because they are motivated by self-care rather than shame or guilt,
people who are body positive engage in healthy habits like exercise and
balanced eating. Positive emotions can enhance physical health.
Body positivity requires one to practice positive thinking towards
their body. Some of the physical health benefits of this way of thinking
are “Increased lifespan,” Lower levels of distress and pain,” Greater
resistance to illnesses,” reduced risk of death from respiratory
conditions,” and “reduced risk of death from infections.”
Practicing body positivity will help increase an individual’s desire
for self-care, leading to better habit-building and helping them define
what wellness means to them.
It also improves mental health. One can reduce anxiety and depression by being body positive.
Having a positive approach to life and accepting uncomfortable
situations has proven to help keep one's mind healthy and resilient. Body positivity is, "the
mindset that everyone is worthy of love and a positive body image,
regardless of how the media and society tries to define beauty or the
ideal body type." When individuals have a positive body image, they reduce the development of Anxiety and depression.
In computer programming, a code smell is any characteristic in the source code of a program that possibly indicates a deeper problem. Determining what is and is not a code smell is subjective, and varies by language, developer, and development methodology.
The term was popularised by Kent Beck on WardsWiki in the late 1990s. Usage of the term increased after it was featured in the 1999 book Refactoring: Improving the Design of Existing Code by Martin Fowler. It is also a term used by agile programmers.
Definition
One
way to look at smells is with respect to principles and quality:
"Smells are certain structures in the code that indicate violation of
fundamental design principles and negatively impact design quality". Code smells are usually not bugs;
they are not technically incorrect and do not prevent the program from
functioning. Instead, they indicate weaknesses in design that may slow
down development or increase the risk of bugs or failures in the future.
Bad code smells can be an indicator of factors that contribute to technical debt. Robert C. Martin calls a list of code smells a "value system" for software craftsmanship.
Often the deeper problem hinted at by a code smell can be uncovered when the code is subjected to a short feedback cycle, where it is refactored
in small, controlled steps, and the resulting design is examined to see
if there are any further code smells that in turn indicate the need for
more refactoring. From the point of view of a programmer charged with
performing refactoring, code smells are heuristics to indicate when to refactor, and what specific refactoring techniques to use. Thus, a code smell is a driver for refactoring.
A 2015 study utilizing automated analysis for half a million source code commits and the manual examination of 9,164 commits determined to exhibit "code smells" found that:
There exists empirical evidence for the consequences of "technical debt", but there exists only anecdotal evidence as to how, when, or why this occurs.
Common wisdom suggests that urgent maintenance activities and
pressure to deliver features while prioritizing time-to-market over code
quality are often the causes of such smells.
Mysterious name: functions, modules, variables or classes that are named in a way that does not communicate what they do or how to use them.
Duplicated code: identical or very similar code that exists in more than one location.
Contrived complexity: forced usage of overcomplicated design patterns where simpler design patterns would suffice.
Shotgun surgery: a single change that needs to be applied to multiple classes at the same time.
Uncontrolled side effects: side effects of coding that
commonly cause runtime exceptions, with unit tests unable to capture the
exact cause of the problem.
Variable mutations: mutations that vary widely enough that
refactoring the code becomes increasingly difficult, due to the actual
value's status as unpredictable and hard to reason about.
Boolean blindness: easy to assert on the opposite value and still type checks.
Class-level smells
Large class: a class that contains too many types or contains many unrelated methods
Feature envy: a class that uses methods of another class excessively.
Inappropriate intimacy: a class that has dependencies on implementation details of another class
Lazy class/freeloader: a class that does too little.
Excessive use of literals: these should be coded as named constants, to improve readability and to avoid programming errors. Additionally, literals
can and should be externalized into resource files/scripts, or other
data stores such as databases where possible, to facilitate localization
of software if it is intended to be deployed in different regions.
Cyclomatic complexity:
too many branches or loops; this may indicate a function needs to be
broken up into smaller functions, or that it has potential for
simplification/refactoring.
Downcasting: a type cast which breaks the abstraction model; the abstraction may have to be refactored or eliminated.
Orphan variable or constant class: a class
that typically has a collection of constants which belong elsewhere
where those constants should be owned by one of the other member
classes.
Data clump:
Occurs when a group of variables are passed around together in various
parts of the program. In general, this suggests that it would be more
appropriate to formally group the different variables together into a
single object, and pass around only the new object instead.
Method-level smells
Too many parameters:
a long list of parameters is hard to read, and makes calling and
testing the function complicated. It may indicate that the purpose of
the function is ill-conceived and that the code should be refactored so
responsibility is assigned in a more clean-cut way.
Long method: a method, function, or procedure that has grown too large.
Excessively short identifiers: the name of a variable should reflect its function unless the function is obvious.
Excessive return of data: a function or method that returns more than what each of its callers needs.
Excessive comments: a class, function or method has irrelevant or trivial comments. A comment on an attribute setter/getter is a good example.
Excessively long line of code (or God Line): A line of code
which is too long, making the code difficult to read, understand, debug,
refactor, or even identify possibilities of software reuse.
An anti-pattern in software engineering, project management, and business processes is a common response to a recurring problem that is usually ineffective and risks being highly counterproductive. The term, coined in 1995 by computer programmer Andrew Koenig, was inspired by the book Design Patterns (which highlights a number of design patterns in software development that its authors considered to be highly reliable and effective) and first published in his article in the Journal of Object-Oriented Programming.
A further paper in 1996 presented by Michael Ackroyd at the Object World West Conference also documented anti-patterns.
It was, however, the 1998 book AntiPatterns
that both popularized the idea and extended its scope beyond the field
of software design to include software architecture and project
management.
Other authors have extended it further since to encompass environmental/organizational/cultural anti-patterns.
Definition
According to the authors of Design Patterns, there are two key elements to an anti-pattern that distinguish it from a bad habit, bad practice, or bad idea:
The anti-pattern is a commonly-used process, structure or
pattern of action that, despite initially appearing to be an appropriate
and effective response to a problem, has more bad consequences than
good ones.
Another solution exists to the problem the anti-pattern is
attempting to address. This solution is documented, repeatable, and
proven to be effective where the anti-pattern is not.
A guide to what is commonly used is a "rule-of-three" similar to that
for patterns: to be an anti-pattern it must have been witnessed
occurring at least three times.
Uses
Documenting anti-patterns can be an effective way to analyze a problem space and to capture expert knowledge.
While some anti-pattern descriptions merely document the adverse
consequences of the pattern, good anti-pattern documentation also
provides an alternative, or a means to ameliorate the anti-pattern.
Software engineering anti-patterns
In software engineering, anti-patterns include the big ball of mud (lack of) design, the God Class (where a single class handles all control in a program rather than control being distributed across multiple classes), magic numbers
(where a unique value with an unexplained meaning or multiple
occurrences which could be replaced with a named constant), and
Poltergeists (ephemeral controller classes that only exist to invoke
other methods on classes).
Big ball of mud
This indicates a software system
that lacks a perceivable architecture. Although undesirable from a
software engineering point of view, such systems are common in practice
due to business pressures, developer turnover and code entropy.
The term was popularized in Brian Foote and Joseph Yoder's 1997 paper of the same name, which defines the term:
A Big Ball of Mud is a haphazardly structured, sprawling, sloppy, duct-tape-and-baling-wire, spaghetti-code
jungle. These systems show unmistakable signs of unregulated growth,
and repeated, expedient repair. Information is shared promiscuously
among distant elements of the system, often to the point where nearly
all the important information becomes global or duplicated.
The overall structure of the system may never have been well defined.
If it was, it may have eroded beyond recognition. Programmers
with a shred of architectural sensibility shun these quagmires. Only
those who are unconcerned about architecture, and, perhaps, are
comfortable with the inertia of the day-to-day chore of patching the
holes in these failing dikes, are content to work on such systems.
— Brian Foote and Joseph Yoder, Big Ball of Mud. Fourth Conference on Patterns Languages of Programs (PLoP '97/EuroPLoP '97) Monticello, Illinois, September 1997
Foote and Yoder have credited Brian Marick as the originator of the 'big ball of mud' term for this sort of architecture.
Project management anti-patterns
Project management anti-patterns included in the Antipatterns book include Blowhard Jamboree (an excess of industry pundits), analysis paralysis,
Viewgraph Engineering (too much time spent making presentations and not
enough on the actual software), Death by Planning (similarly, too much
planning), Fear of Success (irrational fears near to project
completion), The Corncob (difficulties with people), Intellectual
Violence (intimidation through use of jargon or arcane technology),
Irrational Management (bad management habits), Smoke and Mirrors
(excessive use of demos and prototypes by salespeople), Throw It Over
the Wall (forcing fad software engineering practices onto developers
without buy-in), Fire Drill (long periods of monotony punctuated by
short crises), The Feud (conflicts between managers), and e-mail Is
Dangerous (situations resulting from ill-advised e-mail messages).