The exact nature of the poison is still unclear. In the U.S. outbreak, the source of the fish was traced by the Centers for Disease Control and Prevention, and studies of other fish from the same sources showed a hexane-soluble (and hence non-polar lipid) substance that induced similar symptoms in mice; other food-borne poisons commonly found in fish could not be detected. It cannot be inactivated by cooking, as all six CDC cases had consumed cooked or fried fish. Palytoxin has been proposed as a disease model. It has also been suggested that the toxin may have thiaminase activity (i.e. it degrades thiamine, also known as vitamin B1).

It was first described in 1924 in the vicinity of Königsberg, Germany (now Kaliningrad, Russia) on the Baltic coast, in people staying around the northern part of the Vistula Lagoon (German: "Frisches Haff").

Over the subsequent fifteen years, about 1000 cases were reported in people, birds and cats, usually in the summer and fall, and a link was made with the consumption of fish (burbot, eel and pike). Since that time, only occasional reports have appeared of the condition, mostly from the Soviet Union and Germany.

In 1997, six cases of Haff disease were reported in California and Missouri, all after the consumption of buffalo fish ("Ictiobus cyprinellus").

In July and August 2010, dozens of people contracted rhabdomyolysis after eating "Procambarus clarkii" in Nanjing, China. A month later, the Chinese authorities claimed they were victims of Haff disease.

An outbreak was reported in Brooklyn, New York on 18 November 2011, when two household members were stricken by the syndrome after eating buffalo fish. On February 4, 2014 two cases of Haff Disease were reported in Cook County, Illinois following the consumption of buffalo fish.

A group from Brazil has recently identified a Haff Disease outbreak in Bahia state with 71 cases identified.

In laboratory animals, prevention includes a low-stress environment, an adequate amount of nutritional feed, and appropriate sanitation measurements. Because animals likely ingest bacterial spores from contaminated bedding and feed, regular cleaning is a helpful method of prevention. No prevention methods are currently available for wild animal populations.

Although Tyzzer’s disease is commonly found in laboratory animals worldwide, infected wild animal populations have been identified in North America and Australia. Specific locations where the disease has been reported in the United States include Connecticut, Idaho, Iowa, Maryland, Michigan, Montana, Ohio, Wisconsin, and Wyoming. In Canada, it has been reported in British Columbia, Manitoba, Ontario, and Saskatchewan. Outbreaks in these locations are primarily attributed to muskrat populations; however infected cottontail rabbits have been discovered in Maryland.

Bright's disease is a historical classification of kidney diseases that would be described in modern medicine as acute or chronic nephritis. It was characterized by swelling, the presence of albumin in the urine and was frequently accompanied by high blood pressure and heart disease.

Bright's disease was historically 'treated' with warm baths, blood-letting, squill, digitalis, mercuric compounds, opium, diuretics, laxatives, and dietary therapy, including abstinence from alcoholic drinks, cheese and red meat. Arnold Ehret was diagnosed with Bright's disease and pronounced incurable by 24 of Europe's most respected doctors; he designed "The Mucusless Diet Healing System", which apparently cured his illness. William Howard Hay, MD had the illness and, it is claimed, cured himself using the Hay diet.

Pacheco's disease is an acute and often lethal infectious disease in psittacine birds. The disease is caused by a group of herpesviruses, "Psittacid herpesvirus 1" (PsHV-1), which consists of four genotypes. Birds which do not succumb to Pacheco's disease after infection with the virus become asymptomatic carriers that act as reservoirs of the infection. These persistently infected birds, often Macaws, Amazon parrots and some species of conures, shed the virus in feces and in respiratory and oral secretions. Outbreaks can occur when stress causes healthy birds who carry the virus to shed it. Birds generally become infected after ingesting the virus in contaminated material, and show signs of the disease within several weeks.

The main sign of Pacheco's disease is sudden death, sometimes preceded by a short, severe illness. If a bird survives Pacheco's disease following infection with PsHV-1 genotypes 1, 2 or 3, it may later develop internal papilloma disease in the gastrointestinal tract.

Susceptible parrot species include the African gray parrot, and cockatoo. Native Australian birds, such as the eclectus parrot, Bourke's parrot, and budgerigar are susceptible to Pacheco's disease, although the disease itself has not been found in Australia.

Pogosta disease is a viral disease, established to be identical with other diseases, Karelian fever and Ockelbo disease. The names are derived from the words Pogosta, Karelia and Ockelbo, respectively.

The symptoms of the disease include usually rash, as well as mild fever and other flu-like symptoms; in most cases the symptoms last less than 5 days. However, in some cases, the patients develop a painful arthritis. There are no known chemical agents available to treat the disease.

It has long been suspected that the disease is caused by a Sindbis-like virus, a positive-stranded RNA virus belonging to the Alphavirus genus and family Togaviridae. In 2002 a strain of Sindbis was isolated from patients during an outbreak of the Pogosta disease in Finland, confirming the hypothesis.

This disease is mainly found in the Eastern parts of Finland; a typical Pogosta disease patient is a middle-aged person who has been infected through a mosquito bite while picking berries in the autumn. The prevalence of the disease is about 100 diagnosed cases every year, with larger outbreaks occurring in 7-year intervals.

Swine vesicular disease (SVD) is an acute, contagious viral disease of swine caused by the swine vesicular disease virus, an enterovirus. It is characterized by fever and vesicles with subsequent ulcers in the mouth and on the snout, feet, and teats. The pathogen is relatively resistant to heat, and can persist for a long time in salted, dried, and smoked meat products. Swine vesicular disease does not cause economically-important disease, but is important due to its similarity to foot-and-mouth disease.

Ataxia was observed to last for about 8 weeks in the affected animals. The ultimate result is death of the infected animals.

Swine vesicular disease is most commonly brought into a herd by the introduction of a subclinically infected pig.

The disease can be transmitted in feed containing infected meat scraps, or by direct contact with infected feces (such as in an improperly cleaned truck).

The disease is regarded as extremely rare, with an incidence (new number of cases per year) of one case per million people. The patients are predominantly male (86% in a survey of American patients), although in some countries the rate of women receiving a diagnosis of Whipple's disease has increased in recent years. It occurs predominantly in those of Caucasian ethnicity, suggesting a genetic predisposition in that population.

"T. whipplei" appears to be an environmental organism that is commonly present in the gasterointestinal tract but remains asymptomatic. Several lines of evidence suggest that some defect—inherited or acquired—in immunity is required for it to become pathogenic. The possible immunological defect may be specific for "T. whipplei", since the disease is not associated with a substantially increased risk of other infections.

The disease is usually diagnosed in middle age (median 49 years). Studies from Germany have shown that age at diagnosis has been rising since the 1960s.

This is a terminal condition and there is currently no specific treatment for the disease.

Untreated, the disease has a mortality rate upwards of 90%. Cats treated in the early stages can have a recovery rate of 80–90%. Left untreated, the cats usually die from severe malnutrition or complications from liver failure. Treatment usually involves aggressive feeding through one of several methods.

Cats can have a feeding tube inserted by a veterinarian so that the owner can feed the cat a liquid diet several times a day. They can also be force-fed through the mouth with a syringe. If the cat stops vomiting and regains its appetite, it can be fed in a food dish normally. The key is aggressive feeding so the body stops converting fat in the liver. The cat liver has a high regeneration rate and the disease will eventually reverse assuming that irreparable damage has not been done to the liver.

The best method to combat feline hepatic lipidosis is prevention and early detection. Obesity increases the chances of onset. In addition, if a cat stops eating for 1–2 days, it should be taken to a vet immediately. The longer the disease goes untreated, the higher the mortality rate.

The reservoirs of the disease are carrier chickens which could be health but harboring the disease or chronically sick chickens. The disease affects all ages of chickens. The disease can persist in the flock for 2-3 weeks and signs of the disease are seen between 1–3 days post infection. Transmission of the disease is through direct interaction, airborne droplets and drinking contaminated water. Chicken having infection and those carriers contribute highly to the disease transmission

Prevention is through use of Stock coryza-free birds. In other areas culling of the whole flock is a good means of the disease control. Bacterin also is used at a dose of two to reduce brutality of the disease. Precise exposure has also has been used but it should be done with care. Vaccination of the chicks is done in areas with high disease occurrence. Treatment is done by using antibiotics such as erythromycin, Dihydrostreptomycin, Streptomycin sulphonamides, tylosin and Flouroquinolones .

Life expectancy with Fabry disease for males was 58.2 years, compared with 74.7 years in the general population, and for females 75.4 years compared with 80.0 years in the general population, according to registry data from 2001 to 2008. The most common cause of death was cardiovascular disease, and most of those had received kidney replacements.

The twins require the use of wheelchairs for mobility and are unable to speak without the assistance of electronic speaking aids. They experience persistent and painful muscle spasms which are worsened by emotional distress. They are currently living with their parents, with the assistance of hospice workers. Doctors continue to administer tests to the twins in search of a treatment.

No serious long-term effects are known for this disease, but preliminary evidence suggests, if such symptoms do occur, they are less severe than those associated with Lyme disease.

The disease appears to be progressive in nature. The Fields twins started having problems when they were four years old. By the time they had reached the age of nine, they were having difficulty walking and needed frames to assist them with walking. Their muscles have been gradually deteriorating over time. The disease affects the twins' nerves, causing them to make involuntary muscle movements such as trembling in the hands.

The extent of the disease is still unknown as the two women are only 21. However, the disease has had no apparent effect on their brains or personalities. Doctors do not know if the disease is fatal and, if so, what the life expectancy of one with this disease is. If the cause of the disease is genetic, there is a chance that the twins could pass it on to their future children.

Anorexia always precedes liver disease, with the cat refusing to eat enough food for days, or weeks. This may be amplified by frequent vomiting when the cat does choose to eat. A lack of appetite causes the cat to refuse any food, even after it has purged its system of all stomach contents. Severe weight loss proceeds as the liver keeps the cat alive off body fat, causing a yellowing of the skin (jaundice). When the cat runs out of fat to process, severe muscle wasting (cachexia) takes place as the body converts protein into energy. Eventually the body cannot give the brain enough energy to function properly and the cat dies from malnutrition. In addition, an overworked liver can eventually fail causing total system collapse.

Treatment is with penicillin, ampicillin, tetracycline, or co-trimoxazole for one to two years. Any treatment lasting less than a year has an approximate relapse rate of 40%. Recent expert opinion is that Whipple's disease should be treated with doxycycline with hydroxychloroquine for 12 to 18 months. Sulfonamides (sulfadiazine or sulfamethoxazole) may be added for treatment of neurological symptoms.

While risk factors vary with age and gender, most of the common chronic diseases in the US are caused by dietary, lifestyle and metabolic risk factors that are also responsible for the resulting mortality. Therefore, these conditions might be prevented by behavioral changes, such as quitting smoking, adopting a healthy diet, and increasing physical activity. Social determinants are important risk factors for chronic diseases. Social factors, e.g., socioeconomic status, education level, and race/ethnicity, are a major cause for the disparities observed in the care of chronic disease. Lack of access and delay in receiving care result in worse outcomes for patients from minorities and underserved populations. Those barriers to medical care complicate patients monitoring and continuity in treatment.

In the US, Minorities and low-income populations are less likely to access and receive preventive services necessary to detect conditions at an early stage.

The majority of US health care and economic costs associated with medical conditions are for the costs of chronic diseases and conditions and associated health risk behaviors. Eighty-four percent of all health care spending in 2006 was for the 50% of the population who have one or more chronic medical conditions (CDC, 2014).

This illness is a tick-borne disease carried by the lone star tick "Amblyomma americanum". This tick was first proposed as a possible vector of disease in 1984, and the illnesses associated with the tick called "Lyme-like disease", but it was not recognized to be distinct from Lyme disease until the late 1990s.

Several studies have failed to detect "Borrelia burgdorferi", which is the causative agent of Lyme disease, in patients from the southern United States. This disease may be caused by the related bacterium "Borrelia lonestari", which is a spirochete first isolated in culture in 2004. However, this conclusion is controversial since the spirochete is not detected in all cases of the syndrome, which has led some authors to argue that the illness is not caused by a bacterial pathogen.

Pacheco's disease is an eponymously named disease; it is named after the Brazilian veterinarian, Genesio Pacheco, who first came across the disease in 1929, in an outbreak affecting the turquoise-fronted amazon parrot, "Amazona aestiva". Initially, Pacheco's disease was thought to be a manifestation of avian psittacosis. The causative agent of the disease, a herpesvirus, was not identified until 1975.