These conditions nearly all present with an insidious onset of pain referred to the location of the bony damage. Some, notably Kienbock's disease of the wrist, may involve considerable swelling, and Legg-Calvé-Perthes disease of the hip causes the victim to limp. The spinal form, Scheuermann's disease, may cause bending, or kyphosis of the upper spine, giving a "hunch-back" appearance.

Osteochondrosis is a family of orthopedic diseases of the joint that occur in children and adolescents and in rapidly growing animals, particularly pigs, horses, dogs, and broiler chickens. They are characterized by interruption of the blood supply of a bone, in particular to the epiphysis, followed by localized bony necrosis, and later, regrowth of the bone. This disorder is defined as a focal disturbance of endochondral ossification and is regarded as having a multifactorial cause, so no one thing accounts for all aspects of this disease.

Mild or early cases of Pagets are asymptomatic, and so most people are diagnosed with Paget's disease incidentally during medical evaluation for another problem. Approximately 35% of patients with Paget's have symptoms related to the disease when they are first diagnosed. Overall, the most common symptom is bone pain. When symptoms do occur, they may be confused with those of arthritis or other disorders, and so diagnosis may be delayed.

Paget's may first be noticed as an increasing deformity of a person's bones.

Paget's disease affecting the skull may lead to loss of hearing in one or both ears due to compression of the nerves in the inner ear. Rarely, skull involvement may lead to compression of the nerves that supply the eye, leading to vision loss.

Paget's disease is a frequent component of multisystem proteinopathy.

Advanced Paget's disease may lead to other medical conditions, including:

- Osteoarthritis may result from changes in bone shape that alter normal skeletal mechanics. For example, bowing of a femur affected by Paget's may distort overall leg alignment, subjecting the knee to abnormal mechanical forces and accelerating degenerative wear.

- Heart failure is a rare, reported consequence of severe Paget's disease (i.e. more than 40% skeletal involvement). The abnormal bone formation is associated with recruitment of abnormal blood vessels, forcing the cardiovascular system to work harder (pump more blood) to ensure adequate circulation.

- Kidney stones are somewhat more common in patients with Paget's disease.

- Nervous system problems may occur in Paget's disease, resulting from increased pressure on the brain, spinal cord, or nerves, and reduced blood flow to the brain and spinal cord.

- When Paget's disease affects the facial bones, the teeth may become loose. Disturbance in chewing may occur. Chronic dental problems may lead to infection of the jaw bone.

- Angioid streaks may develop, possibly as a result of calcification of collagen or other pathological deposition.

Paget's disease is "not" associated with osteoporosis. Although Paget's disease and osteoporosis can occur in the same patient, they are different disorders. Despite their marked differences, several treatments for Paget's disease are also used to treat osteoporosis.

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.

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.

Adiposis dolorosa, also known as Dercum's disease or Anders disease, is a rare condition characterized by generalized obesity and fatty tumors in the adipose tissue. The tumors are normally painful and found in multiples on the extremities. The cause and mechanism of Dercum's disease remains unknown. Possible causes include nervous system dysfunction, mechanical pressure on nerves, adipose tissue dysfunction, and trauma.

Dercum's disease was first described at Jefferson Medical College by neurologist Francis Xavier Dercum in 1892.

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

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.

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.

There are three main types of the disease each with its own distinctive symptoms.

Type I infantile form, infants will develop normally until about a year old. At this time, the affected infant will begin to lose previously acquired skills involving the coordination of physical and mental behaviors. Additional neurological and neuromuscular symptoms such as diminished muscle tone, weakness, involuntary rapid eye movements, vision loss, and seizures may become present. With time, the symptoms worsen and children affected with this disorder will experience a decreased ability to move certain muscles due to muscle rigidity. The ability to respond to external stimuli will also decrease. Other symptoms include neuroaxonal dystrophy from birth, discoloration of skin, Telangiectasia or widening of blood vessels.

Type II adult form, symptoms are milder and may not appear until the individual is in his or her 30s. Angiokeratomas, an increased coarsening of facial features, and mild intellectual impairment are likely symptoms.

Type III is considered an intermediate disorder. Symptoms vary and can include to be more severe with seizures and mental retardation, or less severe with delayed speech, a mild autistic like presentation, and/or behavioral problems.

Disease onset is typically in early infancy but may occur later in life. Children who have the classic form of Farber disease develop symptoms within the first few weeks of life. These symptoms may include moderately impaired mental ability and problems with swallowing. The liver, heart and kidneys may also be affected. Other symptoms may include vomiting, arthritis, swollen lymph nodes, swollen joints, joint contractures (chronic shortening of muscles or tendons around joints), hoarseness and xanthomas which thicken around joints as the disease progresses. Patients with breathing difficulty may require a breathing tube.

Danon disease (or glycogen storage disease Type IIb) is a metabolic disorder.Danon disease is an X-linked lysosomal and glycogen storage disorder associated with hypertrophic cardiomyopathy, skeletal muscle weakness, and intellectual disability.

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.

Males

In males the symptoms of Danon Disease are more severe. Features of Danon Disease in males are:

- An early age of onset of muscle weakness and heart disease (onset in childhood or adolescence)

- Some learning problems or intellectual disability can be present

- Muscle weakness can be severe and can affect endurance and the ability to walk

- Heart disease (cardiomyopathy) can be severe and can lead to a need for medications. It usually progress to heart failure, commonly complicated by atrial fibrillation and embolic strokes with severe neurological disability, leading to death unless heart transplant is performed.

- Cardiac conduction abnormalities can occur. Wolff-Parkinson-White syndrome is a common conduction pattern in Danon disease.

- Symptoms are usually gradually progressive

- Some individuals may have visual disturbances, and/or retinal pigment abnormalities

- Danon Disease is rare and unfamiliar to most physicians. It can be mistaken for other forms of heart disease and/or muscular dystrophies, including Pompe disease.

Females

In females the symptoms of Danon Disease are less severe. Common symptoms of Danon Disease in females are:

- A later age of onset of symptoms. Many females will not have obvious symptoms until late adolescence or even adulthood.

- Learning problems and intellectual disability are usually ABSENT

- Muscle weakness is often absent or subtle. Some females will tire easily with exercise

- Cardiomyopathy) is often absent in childhood. Some women will develop this in adulthood. Cardiomyopathy can be associated with atrial fibrillation and embolic strokes.

- Cardiac conduction abnormalities can occur. Wolff-Parkinson-White syndrome is a common conduction pattern in Danon disease.

- Symptoms in females progress more slowly than in males.

- Some females may have visual disturbances, and/or retinal pigment abnormalities

- Danon Disease is rare and unfamiliar to most physicians. The milder and more subtle symptoms in females can make it more difficult to diagnose females with Danon Disease

Kidney complications are a common and serious effect of the disease; kidney insufficiency and kidney failure may worsen throughout life. The presence of protein in the urine (which causes foamy urine) is often the first sign of kidney involvement. End-stage kidney failure in those with Fabry disease typically occurs in the third decade of life, and is a common cause of death due to the disease.

Early signs and symptoms of the disorder usually appear around ages 2–10, with gradual onset of vision problems, or seizures. Early signs may be subtle personality and behavior changes, slow learning or regression, repetitive speech or echolalia, clumsiness, or stumbling. Slowing head growth in the infantile form, poor circulation in lower extremities (legs and feet), decreased body fat and muscle mass, curvature of the spine, hyperventilation and/or breath-holding spells, teeth grinding, and constipation may occur.

Over time, affected children suffer mental impairment, worsening seizures, and progressive loss of sight, speech, and motor skills. Batten disease is a terminal disease; life expectancy varies depending on the type or variation.

Females with juvenile Batten disease show first symptoms a year later than males, but on average die a year sooner.

Infants with Krabbe disease are normal at birth. Symptoms begin between the ages of 3 and 6 months with irritability, fevers, limb stiffness, seizures, feeding difficulties, vomiting, and slowing of mental and motor development. In the first stages of the disease, doctors often mistake the symptoms for those of cerebral palsy. Other symptoms include muscle weakness, spasticity, deafness, optic atrophy, optic nerve enlargement, blindness, paralysis, and difficulty when swallowing. Prolonged weight loss may also occur. Juvenile- and adult-onset cases of Krabbe disease also occur, which have similar symptoms but slower progression.

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.

Farber disease (also known as Farber's lipogranulomatosis, ceramidase deficiency, "Fibrocytic dysmucopolysaccharidosis," and "Lipogranulomatosis") is an extremely rare (80 cases reported worldwide to this day) autosomal recessive lysosomal storage disease marked by a deficiency in the enzyme ceramidase that causes an accumulation of fatty material sphingolipids leading to abnormalities in the joints, liver, throat, tissues and central nervous system. Normally, the enzyme ceramidase breaks down fatty material in the body’s cells. In Farber Disease, the gene responsible for making this enzyme is mutated. Hence, the fatty material is never broken down and, instead, accumulates in various parts of the body, leading to the signs and symptoms of this disorder.

Chorea-acanthocytosis (ChAc, also called Choreoacanthocytosis), is a rare hereditary disease caused by a mutation of the gene that directs structural proteins in red blood cells. It belongs to a group of four diseases characterized under the name Neuroacanthocytosis. When a patient's blood is viewed under a microscope, some of the red blood cells appear thorny. These thorny cells are called acanthocytes.

Other effects of the disease may include epilepsy, behaviour changes, muscle degeneration, and neuronal degradation similar to Huntington's Disease. The average age of onset of symptoms is 35 years. The disease is incurable and inevitably leads to premature death.

Some more information about Chorea-acanthocytosis is that it is a very complex autosomal recessive adult-onset neurodegenerative disorder. It often shows itself as a mixed movement disorder, in which chorea, tics, dystonia and even parkinsonism may appear as a symptom.

This disease is also characterized by the presence of a few different movement disorders including chorea, dystonia etc.

Chorea-acanthocytosis is considered an autosomal recessive disorder, although a few cases with autosomal dominant inheritance have been noted.

Adult-onset Still's disease (AOSD) is a form of Still's disease, a rare systemic autoinflammatory disease characterized by the classic triad of persistent high spiking fevers, joint pain, and a distinctive salmon-colored bumpy rash. The disease is considered a diagnosis of exclusion. Levels of the iron-binding protein ferritin may be elevated with this disorder. AOSD may present in a similar manner to other inflammatory diseases and to autoimmune diseases, which must be ruled out before making the diagnosis.

Prognosis is usually favorable but manifestations of the disease affecting the lungs, heart, or kidneys may occasionally cause severe life-threatening complications. It is treated first with steroids such as prednisone. Drugs that block the action of interleukin-1, such as anakinra, can be effective treatments when standard steroid treatments are insufficient.

Schindler disease, also known as Kanzaki disease and alpha-N-acetylgalactosaminidase deficiency is a rare disease found in humans. This lysosomal storage disorder is caused by a deficiency in the enzyme alpha-NAGA (alpha-N-acetylgalactosaminidase), attributable to mutations in the NAGA gene on chromosome 22, which leads to excessive lysosomal accumulation of glycoproteins. A deficiency of the alpha-NAGA enzyme leads to an accumulation of glycosphingolipids throughout the body. This accumulation of sugars gives rise to the clinical features associated with this disorder. Schindler disease is an autosomal recessive disorder, meaning that one must inherit an abnormal allele from both parents in order to have the disease.