Lettuce big-vein disease causes leaf distortion and ruffling in affected lettuce plants.

This disease was first associated in 1983 with a rod-shaped virus named lettuce big-vein associated virus (LBVaV), which is transmitted by the obligately parasitic soil-inhabiting fungus, "Olpidium brassicae". However, in 2000, a second virus, "Mirafiori lettuce virus", was found in lettuce showing big-vein symptoms. Furthermore, since the lettuce infected with this virus alone developed big-vein symptoms, it is considered to be a main agent of the big-vein disease.

Listeriosis is a bacterial infection most commonly caused by "Listeria monocytogenes", although "L. ivanovii" and "L. grayi" have been reported in certain cases. "Listeria" primarily causes infections of the central nervous system (meningitis, meningoencephalitis, brain abscess, cerebritis) and bacteremia in those who are immunocompromised, pregnant women, and those at the extremes of age (newborns and the elderly), as well as gastroenteritis in healthy persons who have been severely infected. "Listeria" is ubiquitous and is primarily transmitted via the oral route after ingestion of contaminated food products, after which the organism penetrates the intestinal tract to cause systemic infections. The diagnosis of listeriosis requires the isolation of the organism from the blood and/or the cerebrospinal fluid. Treatment includes prolonged administration of antibiotics, primarily ampicillin and gentamicin, to which the organism is usually susceptible.

The disease primarily affects older adults, persons with weakened immune systems, pregnant women, and newborns. Rarely, people without these risk factors can also be affected. A person with listeriosis usually has fever and muscle aches, often preceded by diarrhea or other gastrointestinal symptoms. Almost everyone who is diagnosed with listeriosis has invasive infection (meaning that the bacteria spread from their intestines to their blood stream or other body sites). Disease may occur as much as two months after eating contaminated food.

The symptoms vary with the infected person:

- High-risk persons other than pregnant women: Symptoms can include fever, muscle aches, headache, stiff neck, confusion, loss of balance, and convulsions.

- Pregnant women: Pregnant women typically experience only a mild, flu-like illness. However, infections during pregnancy can lead to miscarriage, stillbirth, premature delivery, or life-threatening infection of the newborn.

- Previously healthy persons: People who were previously healthy but were exposed to a very large dose of Listeria can develop a non-invasive illness (meaning that the bacteria have not spread into their blood stream or other body sites). Symptoms can include diarrhea and fever.

If an animal has eaten food contaminated with Listeria and does not have any symptoms, most experts believe that no tests or treatment are needed, even for people at high risk for listeriosis.

Diseases can have a variety of causes, including bacterial infections from an external source such as "Pseudomonas fluorescens" (causing fin rot and fish dropsy), fungal infections (Saprolegnia), mould infections (Oomycete and "Saprolegnia"), parasitic disorders ("Gyrodactylus salaris", "Ichthyophthirius multifiliis", Cryptocaryon, Oodinium causing velvet disease, "Brooklynella hostilis", head and lateral line erosion, Glugea, "Ceratomyxa shasta", "Kudoa thyrsites", "Tetracapsuloides bryosalmonae", "Ceratomyxa shasta" leeches, nematode, Trematoda, Platyhelminthes and fish louse), viral disorders, metabolic disorders, inappropriate water conditions (insufficient aeration, pH, water hardness, temperature and ammonia poisoning) and malnutrition.

External bacterial infections may cause spots or streaks on the body which appear red or orange Dropsy (bloating) is also a sign of a bacterial infection. "False fungal infections" look like fungus but is actually a bacterial infection known as Columnaris. These symptoms may include a white or gray film on the body.

Ornamental fish kept in aquariums are susceptible to numerous diseases. Due to their generally small size and the low cost of replacing diseased or dead fish, the cost of testing and treating diseases is often seen as more trouble than the value of the fish.

Due to the artificially limited volume of water and high concentration of fish in most aquarium tanks, communicable diseases often affect most or all fish in a tank. An improper nitrogen cycle, inappropriate aquarium plants and potentially harmful freshwater invertebrates can directly harm or add to the stresses on ornamental fish in a tank. Despite this, many diseases in captive fish can be avoided or prevented through proper water conditions and a well-adjusted ecosystem within the tank.

Hughes–Stovin syndrome is a rare autoimmune disorder of unknown cause that is characterized by the combination of multiple pulmonary artery aneurysms and deep vein thrombosis. It is named after the two British physicians, John Patterson Hughes and Peter George Ingle Stovin, who first described it in 1959. It is a rare variant of Behçet's disease, which entails more general problems with the circulatory system. Most patients are young adult males between the age of 20-40.

Common clinical presentations include fever, cough, dyspnea and hemoptysis. Radiological features are similar to those of Behçet's disease. There is no satisfactory treatment for this disease.

Verticillium wilt is a wilt disease of over 350 species of eudicot plants caused by six species of Verticillium genus, "V. dahliae", "V. albo-atrum", "V. longisporum", V. nubilum, V. theobromae and

V. tricorpus. (See, for example, Barbara, D.J. & Clewes, E. (2003). "Plant pathogenic Verticillium species: how many of them are there?" Molecular Plant Pathology 4(4).297-305. Blackwell Publishing.) Many economically important plants are susceptible including cotton, tomatoes, potatoes, oilseed rape, eggplants, peppers and ornamentals, as well as others in natural vegetation communities. Many eudicot species and cultivars are resistant to the disease and all monocots, gymnosperms and ferns are immune.

Symptoms are superficially similar to "Fusarium" wilts. There is no chemical control for the disease but crop rotation, the use of resistant varieties and deep plowing may be useful in reducing the spread and impact of the disease.

The signs and symptoms of Lemierre's syndrome vary, but usually start with a sore throat, fever, and general body weakness. These are followed by extreme lethargy, spiked fevers, rigors, swollen cervical lymph nodes, and a swollen, tender or painful neck. Often there is abdominal pain, diarrhea, nausea and vomiting during this phase. These signs and symptoms usually occur several days to 2 weeks after the initial symptoms.

Symptoms of pulmonary involvement can be shortness of breath, cough and painful breathing (pleuritic chest pain). Rarely, blood is coughed up. Painful or inflamed joints can occur when the joints are involved.

Septic shock can also arise. This presents with low blood pressure, increased heart rate, decreased urine output and an increased rate of breathing. Some cases will also present with meningitis, which will typically manifest as neck stiffness, headache and sensitivity of the eyes to light.

Liver enlargement and spleen enlargement can be found, but are not always associated with liver or spleen abscesses.

Other signs and symptoms that may occur:

- Headache (unrelated to meningitis)

- Memory loss

- Muscle pain

- Jaundice

- Decreased ability to open the jaw

- Crepitations are sometimes heard over the lungs

- Pericardial friction rubs as a sign of pericarditis (rare)

- Cranial nerve paralysis and Horner's syndrome (both rare)

Phlegmasia alba dolens (also colloquially known as milk leg or white leg) is part of a spectrum of diseases related to deep vein thrombosis. Historically, it was commonly seen during pregnancy and in mothers who have just given birth. In cases of pregnancy, it is most often seen during the third trimester, resulting from a compression of the left common iliac vein against the pelvic rim by the enlarged uterus. Today, this disease is most commonly (40% of the time) related to some form of underlying malignancy. Hypercoagulability (a propensity to clot formation) is a well-known state that occurs in many cancer states. The incidence of this disease is not well reported.

Banti's syndrome (also known as Banti's disease), named for is Guido Banti., is a chronic congestive enlargement of the spleen resulting in premature destruction of the red blood cells by the spleen.

Enlargement of spleen, ascites, jaundice, and the result of destruction of various blood cells by spleen – anemia, leukopenia, thrombocytopenia, gastrointestinal bleeding – may constitute the presenting symptoms.

The disease presumably begins with a deep vein thrombosis that progresses to total occlusion of the deep venous system. It is at this stage that it is called phlegmasia alba dolens. It is a sudden (acute) process. The leg, then, must rely on the superficial venous system for drainage. The superficial system is not adequate to handle the large volume of blood being delivered to the leg via the arterial system. The result is edema, pain and a white appearance ("alba") of the leg.

The next step in the disease progression is occlusion of the superficial venous system, thereby preventing all venous outflow from the extremity. At this stage it is called phlegmasia cerulea dolens. The leg becomes more swollen and increasingly more painful. Additionally, the edema and loss of venous outflow impedes the arterial inflow. Ischemia with progression to gangrene are potential consequences. Phlegmasia alba dolens is distinguished, clinically, from phlegmasia cerulea dolens in that there is no ischemia.

"Verticillium" spp. attack a very large host range including more than 350 species of vegetables, fruit trees, flowers, field crops, and shade or forest trees. Most vegetable species have some susceptibility, so it has a very wide host range. A list of known hosts is at the bottom of this page.

The symptoms are similar to most wilts with a few specifics to "Verticillium". Wilt itself is the most common symptom, with wilting of the stem and leaves occurring due to the blockage of the xylem vascular tissues and therefore reduced water and nutrient flow. In small plants and seedlings, "Verticillium" can quickly kill the plant while in larger, more developed plants the severity can vary. Some times only one side of the plant will appear infected because once in the vascular tissues, the disease migrates mostly upward and not as much radially in the stem. Other symptoms include stunting, chlorosis or yellowing of the leaves, necrosis or tissue death, and defoliation. Internal vascular tissue discoloration might be visible when the stem is cut.

In "Verticillium", the symptoms and effects will often only be on the lower or outer parts of plants or will be localized to only a few branches of a tree. In older plants, the infection can cause death, but often, especially with trees, the plant will be able to recover, or at least continue living with the infection. The severity of the infection plays a large role in how severe the symptoms are and how quickly they develop.

Lemierre's syndrome (or Lemierre's disease, also known as postanginal shock including sepsis and human necrobacillosis) refers to infectious thrombophlebitis of the internal jugular vein. It most often develops as a complication of a bacterial sore throat infection in young, otherwise healthy adults. The thrombophlebitis is a serious condition and may lead to further systemic complications such as bacteria in the blood or septic emboli.

Lemierre's syndrome occurs most often when a bacterial (e.g., "Fusobacterium necrophorum") throat infection progresses to the formation of a peritonsillar abscess. Deep in the abscess, anaerobic bacteria can flourish. When the abscess wall ruptures internally, the drainage carrying bacteria seeps through the soft tissue and infects the nearby structures. Spread of infection to the nearby internal jugular vein provides a gateway for the spread of bacteria through the bloodstream. The inflammation surrounding the vein and compression of the vein may lead to blood clot formation. Pieces of the potentially infected clot can break off and travel through the right heart into the lungs as emboli, blocking branches of the pulmonary artery that carry blood with little oxygen from the right side of the heart to the lungs.

Sepsis following a throat infection was described by Schottmuller in 1918. However, it was André Lemierre, in 1936, who published a series of 20 cases where throat infections were followed by identified anaerobic sepsis, of whom 18 patients died.

The acute syndrome presents with rapidly progressive severe upper abdominal pain, yellow discoloration of the skin and whites of the eyes, liver enlargement, enlargement of the spleen, fluid accumulation within the peritoneal cavity, elevated liver enzymes, and eventually encephalopathy. The fulminant syndrome presents early with encephalopathy and ascites. Liver cell death and severe lactic acidosis may be present as well. Caudate lobe enlargement is often present. The majority of patients have a slower-onset form of Budd–Chiari syndrome. This can be painless. A system of venous collaterals may form around the occlusion which may be seen on imaging as a "spider's web". Patients may progress to cirrhosis and show the signs of liver failure.

On the other hand, incidental finding of a silent, asymptomatic form may not be a cause for concern.

Budd–Chiari syndrome is a very rare condition, affecting 1 in a million adults. The condition is caused by occlusion of the hepatic veins that drain the liver. It presents with the classical triad of abdominal pain, ascites, and liver enlargement. The formation of a blood clot within the hepatic veins can lead to Budd–Chiari syndrome. The syndrome can be fulminant, acute, chronic, or asymptomatic.

Thrombotic Storm has been seen in individuals of all ages and races. The initial symptoms of TS present in a similar fashion to the symptoms experienced in deep vein thrombosis. Symptoms of a DVT may include pain, swelling and discoloration of the skin in the affected area. As with DVTs patients with TS may subsequently develop pulmonary emboli. Although the presentation of TS and DVTs are similar, TS typically progresses rapidly, with numerous clots occurring within a short period of time. After the formation of the initial clot a patient with TS typically begins a “clotting storm” with the development of multiple clots throughout the body. Rapid progression within a short period of time is often seen, affecting multiple organs systems. The location of the clot is often unusual or found in a spot in the body that is uncommon such as the dural sinus. Patients tend to respond very well to anticoagulation such as coumadin or low molecular weight heparin but may become symptomatic when treatment is withheld.

While the key clinical characteristics of thrombotic storm are still being investigated, it is believed that the clinical course is triggered by a preexisting condition, known as a hypercoagulable state. These can include such things as pregnancy, trauma or surgery. Hypercoagulable states can be an inherited or acquired risk factor that then serves as a trigger to initiate clot formation. However, in a subset of patient with TS a trigger cannot be identified. Typically people with TS will have no personal or family history of coagulations disorders.

Cruveilhier–Baumgarten disease or Pégot-Cruveilhier–Baumgarten disease is a rare medical condition in which the umbilical or paraumbilical veins are distended, with an abdominal wall bruit (the Cruveilhier-Baumgarten bruit) and palpable thrill, portal hypertension with splenomegaly, hypersplenism and oesophageal varices, with a normal or small liver.

It was first described by Pégot in 1833, and then by Jean Cruveilhier (1835) and Paul Clemens von Baumgarten (1907).

Armstrong "et al." (1942) and Steinburg and Galambos (1967) described two different types of the condition:

- Cruveilhier-Baumgarten syndrome: liver cirrhosis or portal hypertension is the cause of the distension of the paraumbilical veins (i.e. an "acquired" condition in which the veins reopen due to high portal pressure).

- Cruveilhier–Baumgarten disease: the distension of the paraumbilical veins is due to failure of umbilical vein closure, with little or no evidence of liver disease found on liver biopsy (i.e. a "congenital" patency of the umbilical vein leading to portal hypertension).

Blood clots are a relatively common occurrence in the general population and are seen in approximately 1-2% of the population by age 60. Typically blood clots develop in the deep veins of the lower extremities, deep vein thrombosis (DVT) or as a blood clot in the lung, pulmonary embolism (PE). A very small number of people who develop blood clots have a more serious and often life-threatening condition, known as Thrombotic Storm (TS). TS is characterized by the development of more than one blood clot in a short period of time. These clots often occur in multiple and sometimes unusual locations in the body and are often difficult to treat. TS may be associated with an existing condition or situation that predisposes a person to blood clots such as injury, infection, or pregnancy. In many cases a risk assessment will identify interventions that will prevent the formation of blood clots.

While the mechanism or pathogenesis is not completely understood mostly due to its rarity, the medical community has developed a new interest in learning more about this syndrome. Dr. Craig S. Kitchens first described TS in six case studies. In these cases he described a collection of similar features observed in six patients, suggesting this may be accounted for by a new syndrome.

Major symptoms of PWS include:

Birthmarks: Effected PWS patients suffer from large, flat, pink staining on the skin. This staining is a result of the capillary malformations that have the tendency to increase the blood flow near the surface of the skin causing the staining. Because of the staining color they are sometimes referred to as “port-wine stains”. “Port-wine stain” or discoloration of the skin due to vascular malformation is also referred as Nevus flammeus.

Hypertrophy: Hypertrophy refers to excessive growth of the bone and soft tissue. In PWS patients a limb is overgrown and hypertrophy is usually seen in the affected limb.

Multiple arteriovenous fistulas: PWS patients also suffer from multiple AVFs that occur in conjunction with capillary malformations. AVFs occur because of abnormal connections between arteries and veins. Normally, blood flows from arteries to capillaries then to veins. But for AFV patients, because of the abnormal artery and vein connections, blood flows directly from arteries into the veins completely bypassing the capillaries. These irregular connections affect the blood circulation and may lead to life-threatening complications such as abnormal bleeding and heart failure. AVFs can be identified by: large, purplish bulging veins, swelling in limbs, decreased in blood pressure, fatigue and heart failure.

Capillary arteriovenous malformations: Vascular system disorder is the cause of the capillary malformations. Here, the capillaries are enlarged and increase the blood flow towards the surface of the skin. Because of the capillary malformations, the skin has multiple small, round, pink or even red dots. For most of the affected individuals, these malformations occur on the face, arms and or legs. The spots may be visible right from birth itself or they may develop during childhood years. If capillary malformations occur by themselves, it is not a huge threat to life. But when these occur in conjunction with AVFs then it is a clear indicator of PWS and may be serious depending on the severity of the malformations.

The Human Phenotype Ontology (HPO) reports of additional symptoms in PWS patients. HPO is an active database that collects and researches on the relationships between phenotypic abnormalities and biochemical networks. This is an useful database as it has information and data on some of the rarest diseases such as PWS. According to HPO, the symptoms which are reported very frequently in PWS patients include: abnormal bleeding, hypertrophy of the lower limb, hypertrophy of the upper limb, nevus flammeus or staining of the skin, peripheral arteriovenous fistula, telangiectasia of the skin. Frequent to occasional symptoms include: varicose veins, congestive heart failure, glaucoma and headache.

Abnormal bleeding: some skin lesions are prone to bleed easily.

Peripheral arteriovenous fistula: abnormal communication between artery and vein that is a direct result of the abnormal connection or wiring between the artery and vein.

Telangiectasia of the skin: Telangiectasia is a condition where tiny blood vessels become widened and form threadlike red lines and or patterns on the skin. Because of their appearance and formation of web-like patterns they are also known as spider veins. These patterns are referred as telangiectases.

Varicose veins: Enlarged, swollen and twisted veins.

Congestive heart failure: This is a condition in which the heart’s ability to meet the requirements of the body is diminished. The cardiac output is decreased and the amount of blood pumped is not adequate enough to keep the circulation from the body and lungs going.

Glaucoma: Glaucoma is a combination of diseases that cause damage to the optic nerve and may result in vision loss and blindness.

Headache: pain in the head.

Renal vein thrombosis (RVT) is the formation of a clot in the vein that drains blood from the kidneys, ultimately leading to a reduction in the drainage of one or both kidneys and the possible migration of the clot to other parts of the body. First described by German pathologist Friedrich Daniel von Recklinghausen in 1861, RVT most commonly affects two subpopulations: newly born infants with blood clotting abnormalities or dehydration and adults with nephrotic syndrome. Nephrotic syndrome, a kidney disorder, causes excessive loss of protein in the urine, hypoalbuminemia, hypercholesterolemia and edema, triggering a hypercoagulable state and increasing chances of clot formation. Other less common causes include hypercoagulable state, cancer, renal transplantation, behcet syndrome, antiphospholipid antibody syndrome or blunt trauma to the back or abdomen. Treatment of RVT mainly focuses on preventing further blood clots in the kidneys and maintaining stable renal function. The use of anticoagulants has become the standard treatment in treating this abnormality. Membranous Glomerulonephritis, the most common cause for nephrotic syndrome in adults, peaks in people ages 40–60 years old and It is twice as likely to occur in men than in women. Since nephrotic syndrome is the most common cause of RVT, people over 40 years old and men are most at risk to develop a renal vein thrombosis.

Nasodigitoacoustic syndrome is congenital and is characterized by a number of nasal, facial and cranial features. These include a broad and high, sometimes depressed nasal bridge (top of the nose, between the eyes) and a flattened nasal tip. This can give the nose a shortened, arch-like appearance. Hypertelorism (unusually wide-set eyes), prominent frontal bones and supraorbital ridge (the eyebrow ridge), bilateral epicanthic folds (an extra flap of skin over the eyelids), a broad forehead and an overall enlarged head circumference have also been observed. A bulging of the upper lip with an exaggerated cupid's bow shape, and maxillary hypoplasia (underdevelopment of the upper jaw) with retraction have also been reported.

Several anomalies affecting the digits (fingers and toes) have been observed with the syndrome. A broadening of the thumbs and big toes (halluces) was reported in two brothers. The broadening was apparent in all distal phalanges of the fingers, although the pinkies were unaffected yet appeared to be clinodactylic (warped, or bent toward the other fingers). Additional eports described this broadness of the thumbs and big toes, with brachydactyly (shortness) in the distal phalanges of the other digits except the pinkies in affected individuals. On X-rays of a two-year-old boy with the disorder, the brachydactyly was shown to be caused by shortening of epiphyses (joint-ends) of the distal phalanges. The broadness and brachydactyly of the big toes in particular may give them a stunted, rounded and stub-like appearance.

The auditory, or "acoustic" abnormalities observed with the syndrome include sensorineural hearing loss and hoarseness. Two affected Turkish brothers with a mild form of this hearing loss, and a hoarse voice were reported. A laryngoscopic examination of both brothers revealed swelling of the vocal cords, and a malformed epiglottis. Sensorineural-associated hearing impairment and hoarsness was also observed in a 10-year-old girl and her father, and in a number of other cases.

Other characteristics seen with the syndrome include developmental delay, growth retardation, pulmonary stenosis (an obstruction of blood-flow from the right ventricle of the heart to the pulmonary artery) with associated dyspnea (shortness of breath), and renal agenesis (failure of the kidneys to develop during the fetal period). Undescended testes, hyperactivity and aggressive behavior have also been noted.

The most common conditions associated with thrombophilia are deep vein thrombosis (DVT) and pulmonary embolism (PE), which are referred to collectively as venous thromboembolism (VTE). DVT usually occurs in the legs, and is characterized by pain, swelling and redness of the limb. It may lead to long-term swelling and heaviness due to damage to valves in the veins. The clot may also break off and migrate (embolize) to arteries in the lungs. Depending on the size and the location of the clot, this may lead to sudden-onset shortness of breath, chest pain, palpitations and may be complicated by collapse, shock and cardiac arrest.

Venous thrombosis may also occur in more unusual places: in the veins of the brain, liver (portal vein thrombosis and hepatic vein thrombosis), mesenteric vein, kidney (renal vein thrombosis) and the veins of the arms. Whether thrombophilia also increases the risk of arterial thrombosis (which is the underlying cause of heart attacks and strokes) is less well established.

Thrombophilia has been linked to recurrent miscarriage, and possibly various complications of pregnancy such as intrauterine growth restriction, stillbirth, severe pre-eclampsia and abruptio placentae.

Protein C deficiency may cause purpura fulminans, a severe clotting disorder in the newborn that leads to both tissue death and bleeding into the skin and other organs. The condition has also been described in adults. Protein C and protein S deficiency have also been associated with an increased risk of skin necrosis on commencing anticoagulant treatment with warfarin or related drugs.

Plum syndrome is a very rare genetic disorder. It is characterized by retinal non-attachment, colobomata, odd facies, eyes set wide, flat face, dislocated hip, abnormal big toe, contractures of the extremities, cleft lip and mono-segmented leucocytes. There may be associated learning difficulties.

Named by Dr. C.M. Plum.

Telangiectasias, also known as spider veins, are small dilated blood vessels near the surface of the skin or mucous membranes, measuring between 0.5 and 1 millimeter in diameter.

These dilated blood vessels can develop anywhere on the body but are commonly seen on the face around the nose, cheeks, and chin. Dilated blood vessels can also develop on the legs, although when they occur on the legs, they often have underlying venous reflux or "hidden varicose veins" (see "Venous reflux" below). When found on the legs, they are found specifically on the upper thigh, below the knee joint, and around the ankles.

Many patients who suffer with spider veins seek the assistance of physicians who specialize in vein care or peripheral vascular disease. These physicians are called vascular surgeons or phlebologists. More recently, interventional radiologists have started treating venous problems.

Some telangiectasias are due to developmental abnormalities that can closely mimic the behaviour of benign vascular neoplasms. They may be composed of abnormal aggregations of arterioles, capillaries, or venules. Because telangiectasias are vascular lesions, they blanch when tested with diascopy.

Telangiectasia is a component of the CREST variant of scleroderma, also known today as limited scleroderma (CREST is an acronym that stands for calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia).