The disease is characterised by bilateral diffuse uveitis, with pain, redness and blurring of vision. The eye symptoms may be accompanied by a varying constellation of systemic symptoms, such as auditory (tinnitus, vertigo, and hypoacusis), neurological (meningismus, with malaise, fever, headache, nausea, abdominal pain, stiffness of the neck and back, or a combination of these factors; meningitis, CSF pleocytosis, cranial nerve palsies, hemiparesis, transverse myelitis and ciliary ganglionitis), and cutaneous manifestations, including poliosis, vitiligo, and alopecia. The vitiligo often is found at the sacral region.

The sequence of clinical events in VKH is divided into four phases: prodromal, acute uveitic, convalescent, and chronic recurrent.

The prodromal phase may have no symptoms, or may mimic a non-specific viral infection, marked by flu-like symptoms that typically last for a few days. There may be fever, headache, nausea, meningismus, dysacusia (discomfort caused by loud noises or a distortion in the quality of the sounds being heard), tinnitus, and/or vertigo. Eye symptoms can include orbital pain, photophobia and tearing. The skin and hair may be sensitive to touch. Cranial nerve palsies and optic neuritis are uncommon.

The acute uveitic phase occurs a few days later and typically lasts for several weeks. This phase is heralded by bilateral panuveitis causing blurring of vision. In 70% of VKH, the onset of visual blurring is bilaterally contemporaneous; if initially unilateral, the other eye is involved within several days. The process can include bilateral granulomatous anterior uveitis, variable degree of vitritis, thickening of the posterior choroid with elevation of the peripapillary retinal choroidal layer, optic nerve hyperemia and papillitis, and multiple exudative bullous serous retinal detachments.

The convalescent phase is characterized by gradual tissue depigmentation of skin with vitiligo and poliosis, sometimes with nummular depigmented scars, as well as alopecia and diffuse fundus depigmentation resulting in a classic orange-red discoloration ("sunset glow fundus") and retinal pigment epithelium clumping and/or migration.

The chronic recurrent phase may be marked by repeated bouts of uveitis, but is more commonly a chronic, low-grade, often subclinical, uveitis that may lead to granulomatous anterior inflammation, cataracts, glaucoma and ocular hypertension. Full-blown recurrences are, however, rare after the acute stage is over. Dysacusia may occur in this phase.

CNS involvement most often occurs as a chronic meningoencephalitis. Lesions tend to occur in the brainstem, the basal ganglia and deep hemispheric white matter and may resemble those of MS. Brainstem atrophy is seen in chronic cases.

Neurological involvements range from aseptic meningitis to vascular thrombosis such as dural sinus thrombosis and organic brain syndrome manifesting with confusion, seizures, and memory loss. Sudden hearing loss (Sensorineural) is often associated with it. They often appear late in the progression of the disease but are associated with a poor prognosis.

Arthralgia is seen in up to half of people, and is usually a non-erosive poly or oligoarthritis primarily of the large joints of the lower extremities.

This is a partial list of human eye diseases and disorders.

The World Health Organization publishes a classification of known diseases and injuries, the International Statistical Classification of Diseases and Related Health Problems, or ICD-10. This list uses that classification.

The most common symptoms are diarrhea, abdominal pain, weight loss, and joint pains. The joint pains may be due to migratory non-deforming arthritis, which may occur many years before any digestive tract symptoms develop; they tend to involve the large joints but can occur in any pattern and tend not to damage the joint surface to the point that the joint becomes deformed. Fever and chills occur in a small proportion of people.

In its more advanced form, malabsorption (insufficient absorption of nutrients from the diet) leads to wasting and the enlargement of lymph nodes in the abdomen. Neurological symptoms (discussed below) are more common in those with the severe form of the abdominal disease. Chronic malabsorptive diarrhea leads to the poor absorption of fat, causing steatorrhea (fatty, offensive stool), flatulence, and abdominal distension. Protein-losing enteropathy may also occur, causing depletion of albumin, a blood protein, which may lead to peripheral edema caused by the lowered oncotic pressures.

Hyperpigmentation of the skin occurs in almost half; some also have skin nodules. Various eye problems, such as uveitis, may occur; this is typically associated with deteriorating vision and pain in the affected eye. Endocarditis (infection of the heart valve) has been reported in a small number of cases, sometimes in people with no other symptoms of Whipple's disease; this is typically noticed as breathlessness and leg swelling due to fluid accumulation as the heart is unable to pump fluid through the body.

Of those affected by Whipple's disease, 10–40% of people have problems related to the involvement of the brain; the symptoms relate to the part of the brain that is affected. The most common problems are dementia, memory loss, confusion, and decreased level of consciousness. Eye movement disturbances and myorhythmia (rapidly repetitive movements of the muscles) of the face, together referred to as "oculomasticatory myorhythmia", are highly characteristic for Whipple's disease. Weakness and poor coordination of part of the body, headaches, seizures, as well as a number of more uncommon neurological features, are present in some cases.

The most common presentation of Milroy Disease is bilateral lower extremity lymphedema, and may also be accompanied by hydrocele.

The following are not classified as diseases of the eye and adnexa (H00-H59) by the World Health Organization:

- (B36.1) Keratomycosis — fungal infection of the cornea

- (E50.6-E50.7) Xerophthalmia — dry eyes, caused by vitamin A deficiency

- (Q13.1) Aniridia — a rare congenital eye condition leading to underdevelopment or even absence of the iris of the eye

The disease typically presents with joint pain, high fevers, a salmon-pink rash, enlargement of the liver and spleen, swollen lymph nodes, and an increased white blood cell count in the blood. Tests for rheumatoid factor and anti-nuclear antibodies are usually negative and serum ferritin is elevated. Patients experiencing a flare-up from Adult-onset Still's disease usually report extreme fatigue, swelling of the lymph nodes and, less commonly, fluid accumulation in the lungs and heart. In rare cases, AOSD can cause aseptic meningitis and sensorineural hearing loss.

Whipple's disease is a rare, systemic infectious disease caused by the bacterium "Tropheryma whipplei". First described by George Hoyt Whipple in 1907 and commonly considered a gastrointestinal disorder, Whipple's disease primarily causes malabsorption but may affect any part of the body including the heart, brain, joints, skin, lungs and the eyes. Weight loss, diarrhea, joint pain, and arthritis are common presenting symptoms, but the presentation can be highly variable and approximately 15% of patients do not have these classic signs and symptoms.

Whipple's disease is significantly more common in men, with 87% of the patients being male. When recognized and treated, Whipple's disease can usually be cured with long-term antibiotic therapy; if the disease is left untreated, it is ultimately fatal.

People with AOSD generally experience one of two patterns in the disease:

- a debilitating pattern of fevers, pain, and other systemic symptoms, or

- a somewhat less aggressive pattern, in which the main symptom is arthritis and chronic joint pain.

One set of 21 adult-onset Still's disease patients were divided into four types, according to clinical course patterns. These included monocyclic systemic disease, polycyclic systemic disease, chronic articular monocyclic systemic disease, and chronic articular polycyclic systemic disease. People with chronic articular disease and polyarticular disease were at higher risk to develop disabling arthritis.

Milroy's disease (MD) is a familial disease characterized by lymphedema, commonly in the legs, caused by congenital abnormalities in the lymphatic system. Disruption of the normal drainage of lymph leads to fluid accumulation and hypertrophy of soft tissues. It is also known as Milroy disease, Nonne-Milroy-Meige syndrome and hereditary lymphedema.

It was named by Sir William Osler for William Milroy, a Canadian physician, who described a case in 1892, though it was first described by Rudolf Virchow in 1863.

Kyrle disease symptoms are chronic and have an onset during adulthood between the ages of 30 and 50 years of age. However, there were reported cases of early onset as early as 5 years of age and late onset as late as 75 years of age. The main symptom is the development of small papules into painless lesions that are surrounded by silvery scales. The lesions are painless, however, there is a chance that the patient may experience extreme urges to itch them. In time, these lesions grow up to a radius of 0.75 inch and develop into red-brown nodules with a central plug of keratin. As more lesions develop, they can come together and form larger keratotic plaques. These lesions are usually observed on the lower extremities, however, can also develop on the upper extremities, such as, the arms, the head and the neck. The only parts of the body that Kyrle disease do not form are the palms, soles, and mucous membranes. Lesions may heal spontaneously without treatment, however, new ones will develop in its place.

Other symptoms that may be observed:

- Hyperkeratotic cone-shaped papular plugs

- Hyperkeratotic verrucous plaques

- Diabetes mellitus

- Hepatic insufficiency

- Presence of albumin in the urine

- Excess sugar in the urine

Although the dermatological changes are the most obvious symptoms of Urbach–Wiethe disease, many patients also have neurological symptoms. About 50–75% of the diagnosed cases of Urbach–Wiethe disease also show bilateral symmetrical calcifications on the medial temporal lobes. These calcifications often affect the amygdala and the periamygdaloid gyri. The amygdala is thought to be involved in processing biologically relevant stimuli and in emotional long term memory, particularly those associated with fear, and both PET and MRI scans have shown a correlation between amygdala activation and episodic memory for strongly emotional stimuli. Therefore, Urbach–Wiethe disease patients with calcifications and lesions in these regions may suffer impairments in these systems. These calcifications are the result of a buildup of calcium deposits in the blood vessels within this brain region. Over time, these vessels harden and the tissue they are a part of dies, causing lesions. The amount of calcification is often related to disease duration. The true prevalence of these calcifications is difficult to accurately state as not all patients undergo brain imaging. Some patients also exhibit epilepsy and neuropsychiatric abnormalities. Epilepsy symptoms could begin with light anxiety attacks and it can be controlled with "Epilum" (Epilepsy Medicine) Other patients present with symptoms similar to schizophrenia while some suffer from mood, anxiety, and psychotic disorders.

The histiocytosis of Rosai–Dorfman disease can occur in lymph nodes, causing lymphadenopathy, or can occur outside lymph nodes in extranodal disease.

Although symptoms can vary greatly between affected individuals, even those within the same family, symptoms normally begin in infancy and are typically a result of thickening skin and mucous membranes. The first symptom is often a weak cry or a hoarse voice due to a thickening of the vocal cords. The hoarse voice can be one of the most striking clinical manifestations of the disease. Lesions and scars also appear on the skin, usually the face and the distal parts of the limbs. This is often the result of poor wound healing and the scarring continues to increase as the patient ages, leaving the skin with a waxy appearance. Skin may be easily damaged as a result of only a minor trauma or injury, leaving many blisters and additional scars. The skin is also usually very dry and wrinkly. White or yellow infiltrates form on the lips, buccal mucosa, tonsils, uvula, epiglottis and frenulum of the tongue. This can lead to upper respiratory tract infection and sometimes requires tracheostomy to relieve the symptom. Too much thickening of the frenulum can restrict tongue movement and may result in speech impediments. Beading of the papules around the eyelids is a very common symptom and is often used as part of a diagnosis of the disease. Some other dermatological symptoms that are sometimes seen but less common include hair loss, parotitis and other dental abnormalities, corneal ulceration, and focal degeneration of the macula.

Full body or localized pain to the extremities (known as acroparesthesia) or gastrointestinal (GI) tract is common in patients with Fabry disease. This acroparesthesia is believed to be related to the damage of peripheral nerve fibers that transmit pain. GI tract pain is likely caused by accumulation of lipids in the small vasculature of the GI tract which obstructs blood flow and causes pain.

Angiokeratomas (tiny, painless papules that can appear on any region of the body, but are predominant on the thighs, around the belly button, buttocks, lower abdomen, and groin) are common.

Anhidrosis (lack of sweating) is a common symptom, and less commonly hyperhidrosis (excessive sweating).

Additionally, patients can exhibit Raynaud's disease-like symptoms with neuropathy (in particular, burning extremity pain).

Ocular involvement may be present showing cornea verticillata (also known as vortex keratopathy), i.e. clouding of the corneas. Keratopathy may be the presenting feature in asymptomatic patients, and must be differentiated from other causes of vortex keratopathy (e.g. drug deposition in the cornea). This clouding does not affect vision.

Other ocular findings can include conjunctival and retinal vascular abnormalities and anterior/posterior spoke-like cataract. Visual reduction from these manifestations is uncommon.

Kyrle disease or hyperkeratosis follicularis et parafollicularis in cutem penetrans is identified as a form of an acquired perforating disease. Other major perforating diseases are elastosis perforans serpiginosa and reactive perforating collagenosis. Recently, however, there is a controversy on categorizing Kyrle disease with perforating dermatosis or a subtype of acquired perforating collagenosis.

Kyrle disease was first described by Josef Kyrle in 1916 when a diabetic woman presented generalized hyperkeratotic nodules. The disease is distinguished by large papules with central keratin plus on the skin, usually on the legs of the patient and is often in conjunction with hepatic, renal or diabetic disorders. It can affect both females and males with a 6:1 ratio. The papules usually show up on the patient with an average age of 30 years. Kyrle disease is a rare disease unless there is a high count of patients with chronic renal failure. The disease seems to be more prevalent in African Americans, which can be correlated to the high incidence of diabetes mellitus and renal failure in the population.

Four cardinal symptoms have sometimes been used as diagnostic criteria:

1. painful, fatty lipomas (benign fatty tumors) across anatomy

2. obesity, frequently in menopausal age

3. weakness and fatigue

4. emotional instability, depression, epilepsy, confusion, and dementia.

There are also potential signs of the disease which are identified as the following:

However, as it is unclear which symptoms are cardinal and which symptoms are minor signs in Dercum's disease, it is unclear which should be used as diagnostic criteria. Researchers have proposed a 'minimal definition' based on symptoms most often part of Dercum's disease: 1) Generalized overweight or obesity. 2) Chronic pain in the adipose tissue. The associated symptoms in Dercum's disease include obesity, fatty deposits, easy bruisability, sleep disturbances, impaired memory, depression, difficulty concentrating, anxiety, rapid heartbeat, shortness of breath, diabetes, bloating, constipation, fatigue, weakness and joint and muscle aches. Regarding the associated symptoms in Dercum's disease, only case reports have been published. No study involving medical examinations has been performed in a large group of patients.

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.

Lymphadenopathy can occur in one or more groups of lymph nodes. Among 358 cases of Rosai–Dorfman disease that Rosai collected in a disease registry for which the location of lymphadenopathy was specified, 87.3% had cervical lymphadenopathy. Axillary, inguinal, and mediastinal lymphadenopathy are also found in Rosai–Dorfman disease.

Fields' disease is considered to be one of the rarest known diseases in the world, with only two diagnosed cases in history. The frequency of this disease is therefore 1 in approximately 3.75 billion (although since the disease manifested in identical twins, the actual frequency is 1 in approximately 7.5 billion). It is named after Welsh twins Catherine and Kirstie Fields, of Llanelli. Fields' disease is a neuromuscular disease, causing muscular degeneration.

The disease was first noticed when the twins were around the age of four. Doctors have been unable to identify it and have not been able to match it to any known diseases. As a result, the Fields sisters have undergone numerous tests, but no treatment has yet been found. No definitive cause has been determined and doctors have generally concluded that they were born with it.

The symptoms and signs of Bright's disease were first described in 1827 by the English physician Richard Bright, after whom the disease was named. In his "Reports of Medical Cases", he described 25 cases of dropsy (edema) which he attributed to kidney disease. Symptoms and signs included: inflammation of serous membranes, hemorrhages, apoplexy, convulsions, blindness and coma. Many of these cases were found to have albumin in their urine (detected by the spoon and candle-heat coagulation), and showed striking morbid changes of the kidneys at autopsy. The triad of dropsy, albumin in the urine and kidney disease came to be regarded as characteristic of Bright's disease. Subsequent work by Bright and others indicated an association with cardiac hypertrophy, which was attributed by Bright to stimulation of the heart. Subsequent work by Mahomed showed that a rise in blood pressure could precede the appearance of albumin in the urine, and the rise in blood pressure and increased resistance to flow was believed to explain the cardiac hypertrophy.

It is now known that Bright's disease is due to a wide range of diverse kidney diseases; thus, the term "Bright's disease" is retained strictly for historical application. The disease was diagnosed frequently in patients with diabetes; at least some of these cases would probably correspond to a modern diagnosis of diabetic nephropathy.

Chronic conditions have often been used to describe the various health related states of the human body such as syndromes, physical impairments, disabilities as well as diseases. Epidemiologists have found interest in chronic conditions due to the fact they contribute to disease, disability, and diminished physical and/or mental capacity.

For example, high blood pressure or hypertension is considered to be not only a chronic condition itself but also correlated to diseases such as heart attack or stroke. Additionally, some socioeconomic factors may be considered as a chronic condition as they lead to disability in daily life. An important one that public health officials in the social science setting have begun highlighting is chronic poverty and racism.

The list below includes these chronic conditions and diseases:

In 2015 the World Health Organisation produced a report on non-communicable diseases, citing the four major types as:

- Cancers

- Cardiovascular diseases, including cerebrovascular disease, heart failure, and ischemic cardiopathy

- Chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease (COPD)

- Diabetes mellitus

Other examples of chronic diseases and health conditions include:

- Addiction

- Alzheimer's disease

- Atrial fibrillation

- Attention deficit hyperactivity disorder

- Autoimmune diseases, such as ulcerative colitis, lupus erythematosus, Crohn's disease, coeliac disease, Hashimoto's thyroiditis, and relapsing polychondritis

- Bipolar disorder

- Blindness

- Cerebral palsy (all types)

- Chronic graft-versus-host disease (GVHD)

- Chronic hepatitis

- Chronic kidney disease

- Chronic osteoarticular diseases, such as osteoarthritis and rheumatoid arthritis

- Chronic pain syndromes, such as post-vasectomy pain syndrome and complex regional pain syndrome

- Depression

- Deafness and hearing impairment

- Eating disorders

- Ehlers–Danlos syndrome (various types)

- Endometriosis

- Epilepsy

- Fibromyalgia

- HIV/AIDS

- Huntington's disease

- Hypertension

- Lyme disease

- Multiple sclerosis

- Myalgic encephalomyelitis ( chronic fatigue syndrome)

- Narcolepsy

- Obesity

- Osteoporosis

- Parkinson's disease

- Periodontal disease

- Postural orthostatic tachycardia syndrome

- Sickle cell anemia and other hemoglobin disorders

- Sleep apnea

- Thyroid disease

- Tobacco Use and Related Conditions