The winter-over syndrome is a condition found in individuals who "winter-over" throughout the Antarctic (or Arctic) winter. It has been observed in inhabitants of research stations in Antarctica, as well as in polar bases such as Thule, Alert and Eureka. It consists of a variety of behavioral and medical disturbances, including irritability, depression, insomnia, absentmindedness, aggressive behavior, and irritable bowel syndrome.

Possible contributing causes of winter-over syndrome include stress, social isolation, subsyndromal seasonal affective disorder and polar T syndrome.

Polar T syndrome is a condition found in polar explorers, caused by a reduction in levels of the thyroid hormone T. Its effects include forgetfulness, cognitive impairment and mood disturbances. It can exhibit itself in a fugue state known as the "Antarctic stare".

It is regarded as one of the contributory causes of winter-over syndrome.

Because CHILD syndrome is a congenital disorder, the symptoms may be present at birth or may develop during the first few weeks of life and continue for the lifetime of the patient.

CHILD syndrome occurs almost exclusively in females. Only 2 known cases have been reported in males, one having a normal 46,XY karyotype, suggesting an early postzygotic somatic mutation.

Cheating at the Paralympic Games has caused scandals that have significantly changed the way in which the International Paralympic Committee (IPC) manages the events.

Testing for performance-enhancing drugs has become increasingly strict and more widespread throughout the Games, with powerlifting seeing the most positive results. Competitors without disabilities have also competed in some Paralympic Games, with the Spanish entry in the intellectually disabled basketball tournament at the 2000 Summer Paralympics being the most controversial.

Hyperventilation syndrome is believed to be caused by psychological factors and by definition has no organic cause. It is one cause of hyperventilation with others including infection, blood loss, heart attack, hypocapnia or alkalosis due to chemical imbalances, decreased cerebral blood flow, and increased nerve sensitivity.

In one study, one third of patients with HVS had "subtle but definite lung disease" that prompted them to breathe too frequently or too deeply.

Many people with panic disorder or agoraphobia will experience HVS. However, most people with HVS do not have these disorders.

The Control of Vibration at Work Regulations 2005, created under the Health and Safety at Work etc. Act 1974. is the legislation in the UK that governs exposure to vibration and assists with preventing HAVS occurring.

Good practice in industrial health and safety management requires that worker vibration exposure is assessed in terms of acceleration amplitude and duration. Using a tool that vibrates slightly for a long time can be as damaging as using a heavily vibrating tool for a short time. The duration of use of the tool is measured as trigger time, the period when the worker actually has their finger on the trigger to make the tool run, and is typically quoted in hours per day. Vibration amplitude is quoted in metres per second squared, and is measured by an accelerometer on the tool or given by the manufacturer. Amplitudes can vary significantly with tool design, condition and style of use, even for the same type of tool.

In the UK, Health and Safety Executive gives the example of a hammer drill which can vary from 6m/s² to 25m/s². HSE publishes a list of typically observed vibration levels for various tools, and graphs of how long each day a worker can be exposed to particular vibration levels. This makes managing the risk relatively straightforward. Tools are given an Exposure Action Value (EAV, the time which a tool can be used before action needs to be taken to reduce vibration exposure) and an Exposure Limit Value (ELV, the time after which a tool may not be used).

In the United States, the National Institute for Occupational Safety and Health published a similar database where values for sound power and vibrations for commonly found tools from large commercial vendors in the United States were surveyed. Further testing is underway for more and newer tools.

The effect of legislation in various countries on worker vibration limits has been to oblige equipment providers to develop better-designed, better-maintained tools, and for employers to train workers appropriately. It also drives tool designers to innovate to reduce vibration. Some examples are the easily manipulated mechanical arm (EMMA) and the suspension mechanism designed into chainsaws.

The original traditional treatment of breathing into a paper bag to control psychologically based hyperventilation syndrome (which is now almost universally known and often shown in movies and TV dramas) was invented by New York City physician (later radiologist), Alexander Winter, M.D. [1908-1978], based on his experiences in the U.S. Army Medical Corps during World War II and published in the Journal of the American Medical Association in 1951. Because other medical conditions can be confused with hyperventilation, namely asthma and heart attacks, most medical studies advise against using a paper bag since these conditions worsen when CO levels increase.

Excessive exposure to hand arm vibrations can result in various patterns of diseases casually known as HAVS or VWF. This can affect nerves, joints, muscles, blood vessels or connective tissues of the hand and forearm:

- Tingling 'whiteness' or numbness in the fingers (blood vessels and nerves affected): This may not be noticeable at the end of a working day, and in mild cases may affect only the tips of the fingers. As the condition becomes more severe, the whole finger down to the knuckles may become white. Feeling may also be lost.

- Fingers change colour (blood vessels affected): With continued exposure the person may suffer periodic attacks in which the fingers change colour when exposed to the cold. Initially the fingers rapidly become pale and feeling is lost. This phase is followed by an intense red flush (sometimes preceded by a dusky bluish phase) signalling the return of blood circulation to the fingers and is usually accompanied by uncomfortable throbbing.

- Loss of manual dexterity (nerves and muscles affected): In more severe forms, attacks may occur frequently in cold weather, not only at work, but during leisure activities, such as gardening, car washing or even watching outdoor sports and may last up to an hour causing considerable pain and loss of manual dexterity and reduced grip strength.

In extreme cases, the sufferer may lose fingers. The effects are cumulative. When symptoms first appear, they may disappear after a short time. If exposure to vibration continues over months or years, the symptoms can worsen and become permanent.

Although there is no known cause for piblokto, Western scientists have attributed the disorder to the lack of sun, the extreme cold, and the desolate state of most villages in the region. A reason for this disorder present in this culture may be due to the isolation of their cultural group.

This culture-bound syndrome is possibly linked to vitamin A toxicity (hypervitaminosis A). The native Inughuit diet or Eskimo nutrition provides rich sources of vitamin A through the ingestion of livers, kidneys, and fat of arctic fish and mammals and is possibly the cause or a causative factor. This causative factor is through the disturbance that has been reported for males, females, adults, children, and dogs. The ingestion of organ meats, particularly the livers of some Arctic mammals, such as the polar bear and bearded seal, where the vitamin is stored in toxic quantities, can be fatal to most people.

Inughuit tradition states that it is caused by evil spirits possessing the living. Shamanism and animism are dominant themes in Inughuit traditional beliefs with the angakkuq (healer) acting as a mediator with the supernatural forces. Angakkuit use trance states to communicate with spirits and carry out faith healing. There is a view among the Inughuit that individuals entering trance states should be treated with respect given the possibility of a new "revelation" emerging as a result. Treatment in piblokto cases usually involves allowing the episode to run its course without interference. While piblokto can often be confused with other conditions, (including epilepsy) in which failure to intervene can lead to the victim coming to harm, most cases tend to be more typical.

Doping in Russian sports has a systemic nature. Russia has had 51 Olympic medals stripped for doping violations – the most of any country, four times the number of the runner-up, and more than a third of the global total. From 2011 to 2015, more than a thousand Russian competitors in various sports, including summer, winter, and Paralympic sports, benefited from a cover-up.

Winter depression is a common slump in the mood of some inhabitants of most of the Nordic countries. It was first described by the 6th century Goth scholar Jordanes in his "Getica" wherein he described the inhabitants of Scandza (Scandinavia). Iceland, however, seems to be an exception. A study of more than 2000 people there found the prevalence of seasonal affective disorder and seasonal changes in anxiety and depression to be unexpectedly "low" in both sexes. The study's authors suggested that propensity for SAD may differ due to some genetic factor within the Icelandic population. A study of Canadians of wholly Icelandic descent also showed low levels of SAD. It has more recently been suggested that this may be attributed to the large amount of fish traditionally eaten by Icelandic people, in 2007 about 90 kilograms per person per year as opposed to about 24 kg in the US and Canada, rather than to genetic predisposition; a similar anomaly is noted in Japan, where annual fish consumption in recent years averages about 60 kg per capita. Fish are high in vitamin D. Fish also contain docosahexaenoic acid (DHA), which help with a variety of neurological dysfunctions.

With rest and quadriceps flexibility exercises the condition settles with no secondary disability. Sometimes, if the condition does not settle, calcification appears in the ligament. This condition is comparable to Osgood-Schlatter’s disease and usually recovers spontaneously. If rest fails to provide relief, the abnormal area is removed and the paratenon is stripped.

Sinding-Larsen and Johansson syndrome, named after Swedish surgeon Sven Christian Johansson (1880-1959), and Christian Magnus Falsen Sinding-Larsen (1866-1930), a Norwegian physician, is an analogous condition to Osgood–Schlatter disease involving the patellar tendon and the lower margin of the patella bone, instead of the upper margin of the tibia, as is the case in Osgood-Schlatter. This variant was discovered in 1908, during a winter indoor Olympic qualifier event in Scandinavia. Sever's disease is a similar condition affecting the heel.

This condition called Sinding-Larsen and Johansson syndrome was described independently by Sinding-Larsen in 1921 and Johansson in 1922.

Aicardi–Goutières syndrome (AGS), which is completely distinct from the similarly named Aicardi syndrome, is a rare, usually early onset childhood, inflammatory disorder most typically affecting the brain and the skin (neurodevelopmental disorder). The majority of affected individuals experience significant intellectual and physical problems, although this is not always the case. The clinical features of AGS can mimic those of "in utero" acquired infection, and some characteristics of the condition also overlap with the autoimmune disease systemic lupus erythematosus (SLE). Following an original description of eight cases in 1984, the condition was first referred to as 'Aicardi–Goutières syndrome' (AGS) in 1992, and the first international meeting on AGS was held in Pavia, Italy, in 2001.

AGS can occur due to mutations in any one of a number of different genes, of which seven have been identified to date, namely: TREX1, RNASEH2A, RNASEH2B, RNASEH2C (which together encode the Ribonuclease H2 enzyme complex), SAMHD1, ADAR1, and IFIH1 (coding for MDA5). This neurological disease occurs in all populations worldwide, although it is almost certainly under-diagnosed. To date (2014) at least 400 cases of AGS are known.

Susac's syndrome is named for Dr. John Susac (1940–2012), of Winter Haven, Florida, who first described it in 1979. Susac's syndrome is a very rare disease, of unknown cause, and many persons who experience it do not display the bizarre symptoms named here. Their speech can be affected, such as the case of a female of late teens who suffered speech issues and hearing problems, and many experience unrelenting and intense headaches and migraines, some form of hearing loss, and impaired vision. The problem usually corrects itself, but this can take up to five years. In some cases, subjects can become confused. The syndrome usually affects women around the age of 18 years, with female to male ratio of cases of 2:1.

William F. Hoyt was the first to call the syndrome "Susac syndrome" and later Robert Daroff asked Dr. Susac to write an editorial in Neurology about the disorder and to use the eponym of Susac syndrome in the title, forever linking this disease with him.

In China, frigophobia is known as Wei Han Zheng (畏寒症). From the standpoint of traditional Chinese beliefs, the disorder is highly influenced by an imbalance of yin (the female element) and yang (the male element). Chinese traditional beliefs also states that working women are particularly susceptible to frigophobia, triggered by a combination of stress, menopause, pregnancy and other disorders such as anemia. During winter, these women are likely to experience coldness in extremities and back pains caused by the disorder.

It is believed that the disorder can be treated using a combination of diet in order to re-balance the yin and yang. A common dietary treatment include:

- Chicken soup

- Turnip juice mixed with ginger juice and honey, three times a day

- Red tea with ginger juice and sugar, two times a day

- Foods containing yeast (e.g. bread)

- Spices (ginger, chili pepper)

- Vinegar diluted in water

It is also believed that the dietary treatment will be more effective if taken in conjunction with an acupuncture routine.

A case study of a 45-year-old Singaporean housewife with frigophobia was studied and the results concluded: frigophobia is closely related to, and strongly influenced by cultural beliefs. Generally speaking, in therapy, treatments would consist of using low dose of anxiolytics and antidepressants, and psychological interventions. But usually when Asian women are notified of the illness, they would adopt various measures to recover. These include withdrawal from workforce, avoid exposure to cold air and wind, and most importantly they will take dietary precautions. It would be rather important to consider the patient’s cultural beliefs about the “illness” in comparison to the therapist’s belief of the illness, and then find a negotiable approach for the treatment.

In the United States, a diagnosis of seasonal affective disorder was first proposed by Norman E. Rosenthal, M.D. in 1984. Rosenthal wondered why he became sluggish during the winter after moving from sunny South Africa to (cloudy in winter) New York. He started experimenting increasing exposure to artificial light, and found this made a difference. In Alaska it has been established that there is a SAD rate of 8.9%, and an even greater rate of 24.9% for subsyndromal SAD.

Around 20% of Irish people are affected by SAD, according to a survey conducted in 2007. The survey also shows women are more likely to be affected by SAD than men. An estimated 10% of the population in the Netherlands suffer from SAD.

KWE is inherited in an autosomal dominant manner. This means that the defective gene responsible for the disorder is located on an autosome (chromosome 8 is an autosome), and one copy of the defective gene is sufficient to cause the disorder when inherited from a parent who also has the disorder.KWE can begin as a spontaneous mutation, first appearing in an individual with no previous family history of the disorder. This may be due to a genetic predisposition for the disorder, possibly connected to the Oudtshoorn ancestral line.

KWE is of unknown cause, as at the present time, no specific mutation of any gene has been established as the cause of the disorder. Research has shown, however, that the gene involved is located on human chromosome 8.

A candidate gene is a gene that is suspected to cause a disease or disorder. In KWE, this gene is known to be located in the area between chromosome 8q22 and 8q23. Within this region, the occurrence of loss of heterozygosity (simultaneous loss of function in both alleles of a gene) has been associated with malignancy, including certain types of breast and lung cancer. During the investigation for a KWE candidate gene in this same region, twelve protein transcripts were evaluated between microsatellite markers D8S550 and D8S1759, which is a critical area shown to be the source of KWE pathogenesis. Among the twelve transcripts identified, one corresponded to the "BLK" gene, which encodes the enzyme "B-lymphoid tyrosine kinase". Four other of these transcripts included a myotubularin ("MTMR8"), a potential human homologue of the mouse "Amac1" enzyme, a transcript similar to the mouse "L-threonine 3-dehydrogenase" gene, and one similar to a human oncogene. The remaining seven transcripts did not resemble any currently known genes. In all, none of the twelve transcripts displayed any evidence of pathogenic involvement with KWE. As a transcriptional map of this critical area is being drawn, based on microsatellite identification, haplotype analysis and other measures; localization of the gene associated with KWE pathogenesis is an ongoing process.

Piblokto, also known as pibloktoq and Arctic hysteria, is a condition most commonly appearing in Inughuit (Greenlandic Inuit) societies living within the Arctic Circle. Piblokto is a culture-specific hysterical reaction in Inuit, especially women, who may perform irrational or dangerous acts, followed by amnesia for the event. Piblokto may be linked to repression of the personality of Inuit women. The condition appears most commonly in winter. It is considered to be a form of a culture-bound syndrome, although more recent studies (see "Skepticism" section) question whether it exists at all. Piblokto is also part of the glossary of cultural bound syndromes found in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).

Fifty percent of patients with acute Sydenham's chorea spontaneously recover after two to six months whilst mild or moderate chorea or other motor symptoms can persist for up to and over two years in some cases. Sydenham's is also associated with psychiatric symptoms with obsessive compulsive disorder being the most frequent manifestation.

Juvenile plantar dermatosis (also known as "Atopic winter feet," "Dermatitis plantaris sicca," "Forefoot dermatitis," "Moon-boot foot syndrome," and "Sweaty sock dermatitis") is a condition usually seen in children between the ages of 3 and 14, and involves the cracking and peeling of weight bearing areas of the soles of the feet. One of the earliest descriptions was made by British dermatologist Darrell Wilkinson.

Laboratory: normal metabolic and infective screening. An increase in the number of white cells (particularly lymphocytes) in the CSF, and high levels of interferon-alpha activity and neopterin in the CSF are important clues - however, these features are not always present. More recently, a persistent elevation of mRNA levels of interferon-stimulated gene transcripts have been recorded in the peripheral blood of almost all cases of AGS with mutations in "TREX1", "RNASEH2A", "RNASEH2C", "SAMHD1", "ADAR1" and "IFIH1", and in 75% of patients with mutations in "RNASEH2B". These results are irrespective of age. Thus, this interferon signature appears to be a very good marker of disease.

Genetics: pathogenic mutations in any of the seven genes known to be involved in AGS.

Susac's syndrome (retinocochleocerebral vasculopathy) is a very rare form of microangiopathy characterized by encephalopathy, branch retinal artery occlusions and hearing loss. The cause is unknown but the current thinking is that antibodies are produced against endothelial cells in tiny arteries which leads to damage and the symptoms related to the illness. Despite this being an extremely rare disease, there are 4 registries collecting data on the illness; two are in the United States, one is in Germany and the fourth is in Portugal.