Otitis is a general term for inflammation or infection of the ear, in both humans and other animals.

It is subdivided into the following:

- "Otitis externa", external otitis, or "swimmer's ear" involves the outer ear and ear canal. In external otitis, the ear hurts when touched or pulled.

- "Otitis media" or middle ear infection involves the middle ear. In otitis media, the ear is infected or clogged with fluid behind the ear drum, in the normally air-filled middle-ear space. This very common childhood infection sometimes requires a surgical procedure called "myringotomy" and tube insertion.

- "Otitis interna" or labyrinthitis involves the inner ear. The inner ear includes sensory organs for balance and hearing. When the inner ear is inflamed, "vertigo" is a common symptom.

An integral symptom of acute otitis media is ear pain; other possible symptoms include fever, and irritability (in infants). Since an episode of otitis media is usually precipitated by an upper respiratory tract infection (URTI), there are often accompanying symptoms like a cough and nasal discharge.

Discharge from the ear can be caused by acute otitis media with perforation of the ear drum, chronic suppurative otitis media, tympanostomy tube otorrhea, or acute otitis externa. Trauma, such as a basilar skull fracture, can also lead to discharge from the ear due to cerebral spinal drainage from the brain and its covering (meninges).

The main symptom of labyrinthitis is severe vertigo. Rapid and undesired eye motion (nystagmus) often results from the improper indication of rotational motion. Nausea, anxiety, and a general ill feeling are common due to the distorted balance signals that the brain receives from the inner ear.

In most cases, the condition tends to be self-limiting. In 95% or greater, vestibular neuritis is a one-time experience with most people fully recovering.

Recovery from acute labyrinthine inflammation generally takes from one to six weeks, but it is not uncommon for residual symptoms (dysequilibrium and/or dizziness) to last for a couple of months.

Recovery from a temporary damaged inner ear typically follows two phases:

1. An acute period, which may include severe vertigo and vomiting

2. approximately two weeks of sub-acute symptoms and rapid recovery

Otitis media is a group of inflammatory diseases of the middle ear. The two main types are acute otitis media (AOM) and otitis media with effusion (OME). AOM is an infection of abrupt onset that usually presents with ear pain. In young children this may result in pulling at the ear, increased crying, and poor sleep. Decreased eating and a fever may also be present. OME is typically not associated with symptoms. Occasionally a feeling of fullness is described. It is defined as the presence of non-infectious fluid in the middle ear for more than three months. Chronic suppurative otitis media (CSOM) is middle ear inflammation of greater than two weeks that results in episodes of discharge from the ear. It may be a complication of acute otitis media. Pain is rarely present. All three may be associated with hearing loss. The hearing loss in OME, due to its chronic nature, may affect a child's ability to learn.

The cause of AOM is related to childhood anatomy and immune function. Either bacteria or viruses may be involved. Risk factors include exposure to smoke, use of pacifiers, and attending daycare. It occurs more commonly among Indigenous peoples and those who have Down syndrome. OME frequently occurs following AOM and may be related to viral upper respiratory infections, irritants such as smoke, or allergies. Looking at the eardrum is important for making the correct diagnosis. Signs of AOM include bulging or a lack of movement of the tympanic membrane from a puff of air. New discharge not related to otitis externa also indicates the diagnosis.

A number of measures decrease the risk of otitis media including pneumococcal and influenza vaccination, exclusive breastfeeding for the first six months of life, and avoiding tobacco smoke. The use of pain medications for AOM is important. This may include paracetamol (acetaminophen), ibuprofen, benzocaine ear drops, or opioids. In AOM, antibiotics may speed recovery but may result in side effects. Antibiotics are often recommended in those with severe disease or under two years old. In those with less severe disease they may only be recommended in those who do not improve after two or three days. The initial antibiotic of choice is typically amoxicillin. In those with frequent infections tympanostomy tubes may decrease recurrence. In children with otitis media with effusion antibiotics may increase resolution of symptoms, but may cause diarrhoea, vomiting and skin rash.

Worldwide AOM affect about 11% of people a year (about 325 to 710 million cases). Half the cases involve children less than five years of age and it is more common among males. Of those affected about 4.8% or 31 million develop chronic suppurative otitis media. Before the age of ten OME affects about 80% of children at some point. Otitis media resulted in 3,200 deaths in 2015 – down from 4,900 deaths in 1990.

Some common symptoms and signs of mastoiditis include pain, tenderness, and swelling in the mastoid region. There may be ear pain (otalgia), and the ear or mastoid region may be red (erythematous). Fever or headaches may also be present. Infants usually show nonspecific symptoms, including anorexia, diarrhea, or irritability. Drainage from the ear occurs in more serious cases, often manifest as brown discharge on the pillowcase upon waking.

Vertigo that is caused by problems with the inner ear or vestibular system, which is composed of the semicircular canals, the vestibule (utricle and saccule), and the vestibular nerve is called "peripheral", "otologic" or "vestibular" vertigo. The most common cause is benign paroxysmal positional vertigo (BPPV), which accounts for 32% of all peripheral vertigo. Other causes include Ménière's disease (12%), superior canal dehiscence syndrome, labyrinthitis, and visual vertigo. Any cause of inflammation such as common cold, influenza, and bacterial infections may cause transient vertigo if it involves the inner ear, as may chemical insults (e.g., aminoglycosides) or physical trauma (e.g., skull fractures). Motion sickness is sometimes classified as a cause of peripheral vertigo.

People with peripheral vertigo typically present with mild to moderate imbalance, nausea, vomiting, hearing loss, tinnitus, fullness, and pain in the ear. In addition, lesions of the internal auditory canal may be associated with facial weakness on the same side. Due to a rapid compensation process, acute vertigo as a result of a peripheral lesion tends to improve in a short period of time (days to weeks).

Vertigo that arises from injury to the balance centers of the central nervous system (CNS), often from a lesion in the brainstem or cerebellum, is called "central" vertigo and is generally associated with less prominent movement illusion and nausea than vertigo of peripheral origin. Central vertigo may have accompanying neurologic deficits (such as slurred speech and double vision), and pathologic nystagmus (which is pure vertical/torsional). Central pathology can cause disequilibrium which is the sensation of being off balance. The balance disorder associated with central lesions causing vertigo is often so severe that many patients are unable to stand or walk.

A number of conditions that involve the central nervous system may lead to vertigo including: lesions caused by infarctions or hemorrhage, tumors present in the cerebellopontine angle such as a vestibular schwannoma or cerebellar tumors, epilepsy, cervical spine disorders such as cervical spondylosis, degenerative ataxia disorders, migraine headaches, lateral medullary syndrome, Chiari malformation, multiple sclerosis, parkinsonism, as well as cerebral dysfunction. Central vertigo may not improve or may do so more slowly than vertigo caused by disturbance to peripheral structures.

Acute adenoiditis is characterized by fever, runny nose, nasal airway obstruction resulting in predominantly oral breathing, snoring and sleep apnea, Rhinorrhea with serous secretion in viral forms and mucous-purulent secretion in bacterial forms. In cases due to viral infection symptoms usually recede spontaneously after 48 hours, symptoms of bacterial adenoiditis typically persist up to a week. Adenoiditis is sometimes accompanied by tonsillitis. Repeated adenoiditis may lead to enlarged adenoids.

Adenoiditis is the inflammation of the adenoid tissue, usually caused by an infection. Adenoiditis is treated using medication (antibiotics and/or steroids) or surgical intervention.

Adenoiditis may produce cold-like symptoms. However, adenoiditis symptoms often persist for ten or more days, and often include pus-like discharge from nose.

The infection cause is usually viral. However, if the adenoiditis is caused by a bacterial infection, antibiotics may be prescribed for treatment. A steroidal nasal spray may also be prescribed in order to reduce nasal congestion. Severe or recurring adenoiditis may require surgical removal of the adenoids (adenotonsillectomy).

Mastoiditis is the result of an infection that extends to the air cells of the skull behind the ear. Specifically, it is an inflammation of the mucosal lining of the mastoid antrum and mastoid air cell system inside the mastoid process. The mastoid process is the portion of the temporal bone of the skull that is behind the ear which contains open, air-containing spaces. Mastoiditis is usually caused by untreated acute otitis media (middle ear infection) and used to be a leading cause of child mortality. With the development of antibiotics, however, mastoiditis has become quite rare in developed countries where surgical treatment is now much less frequent and more conservative, unlike former times. Additionally, there is no evidence that the drop in antibiotic prescribing for otitis media has increased the incidence of mastoiditis, raising the possibility that the drop in reported cases is due to a confounding factor such as childhood immunizations against Haemophilus and Streptococci. Untreated, the infection can spread to surrounding structures, including the brain, causing serious complications.

Many patients will report a history of vertigo as a result of fast head movements. Many patients are also capable of describing the exact head movements that provoke their vertigo. Purely horizontal nystagmus and symptoms of vertigo lasting more than one minute can also indicate BPPV occurring in the horizontal semicircular canal.

Patients do not experience other neurological deficits such as numbness or weakness, and if these symptoms are present, a more serious etiology, such as posterior circulation stroke or ischemia, must be considered.

The spinning sensation experienced from BPPV is usually triggered by movement of the head, will have a sudden onset, and can last anywhere from a few seconds to several minutes. The most common movements patients report triggering a spinning sensation are tilting their heads upwards in order to look at something, and rolling over in bed.

Conductive hearing loss makes all sounds seem faint or muffled. The hearing loss is worse in low frequencies.

Congenital conductive hearing loss is usually identified through newborn hearing screening or may be identified because the baby has microtia or other facial abnormalities. Conductive hearing loss developing during childhood is usually due to otitis media with effusion and may present with speech and language delay or difficulty hearing. Later onset of conductive hearing loss may have an obvious cause such as an ear infection, trauma or upper respiratory tract infection or may have an insidious onset related to chronic middle ear disease, otosclerosis or a tumour of the naso-pharynx. Earwax is a very common cause of a conductive hearing loss which may present suddenly when water gets behind the wax and this blocks the ear canal.

Fluid accumulation is the most common cause of conductive hearing loss in the middle ear, especially in children. Major causes are ear infections or conditions that block the eustachian tube, such as allergies or tumors. Blocking of the eustachian tube leads to decreased pressure in the middle ear relative to the external ear, and this causes decreased motion of both the ossicles and the tympanic membrane.

- acute or serous otitis media

- otitis media with effusion or 'glue ear'

- Perforated eardrum

- Chronic suppurative otitis media (CSOM)

- Cholesteatoma

- Otosclerosis, abnormal growth of bone in or near the middle ear

- middle ear tumour

- ossicular discontinuity as a consequence of infection or temporal bone trauma

- Congenital malformation of the ossicles. This can be an isolated phenomenon or can occur as part of a syndrome where development of the 1st and 2nd branchial arches is seen such as in Goldenhar syndrome, Treacher Collins syndrome, branchio-oto-renal syndrome etc.

- Barotrauma unequal air pressures in the external and middle ear. This can temporarily occur, for example, by the environmental pressure changes as when shifting altitude, or inside a train going into a tunnel. It is managed by any of various methods of ear clearing manoeuvres to equalize the pressures, like swallowing, yawning, or the Valsalva manoeuvre. More severe barotrauma can lead to middle ear fluid or even permanent sensorineural hearing loss.

Vertigo, a distinct process sometimes confused with the broader term, dizziness, accounts for about six million clinic visits in the United States every year; between 17 and 42% of these patients are eventually diagnosed with BPPV.

Other causes of vertigo include:

- Motion sickness/motion intolerance: a disjunction between visual stimulation, vestibular stimulation, and/or proprioception

- Visual exposure to nearby moving objects (examples of optokinetic stimuli include passing cars and falling snow)

- Other diseases: (labyrinthitis, Ménière's disease, and migraine, etc.)

Congenital disorders of the salivary glands are rare, but may include:

- Aplasia

- Atresia

- Ectopic salivary gland tissue

- Stafne defect - an uncommon condition which some consider to be an anatomic variant rather than a true disease. It is thought to be created by an ectopic portion of salivary gland tissue which causes the bone of the mandible to remodel around the tissue, creating an apparent cyst like radiolucent area on radiographs. Classically, this lesion is discovered as a chance finding, since it causes no symptoms. It appears below the inferior alveolar nerve canal in the posterior region of the mandible.

Infections involving the salivary glands can be viral or bacterial (or rarely fungal).

- Mumps is the most common viral sialadenitis. It usually occurs in children, and there is preauricular pain (pain felt in front of the ear), swelling of the parotid, fever, chills, and headaches.

- Bacterial sialadentitis is usually caused by ascending organisms from the oral cavity. Risk factors include reduced salivary flow rate.

- Human immunodeficiency virus-associated salivary gland disease (HIV-SGD).

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.

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.

Most symptoms of people with post-viral cerebellar ataxia deal to a large extent with the movement of the body. Some common symptoms that are seen are clumsy body movements and eye movements, difficulty walking, nausea, vomiting, and headaches.

Differential diagnosis may include:

- Opsoclonus-myoclonus-ataxia syndrome

- Miller-Fisher syndrome

- Meningoencephalitis

- Cerebral abscess

- Tumor

- Hydrocephalus

- Inner-ear Disease

- Acute Vestibulitis

- Acute Labyrinthitis

Dizziness is an impairment in spatial perception and stability. Because the term "dizziness" is imprecise, it can refer to vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness.

One can induce dizziness by engaging in disorientating activities such as spinning.

- Vertigo is the sensation of spinning or having one's surroundings spin about them. Many people find vertigo very disturbing and often report associated nausea and vomiting. It represents about 25% of cases of occurrences of dizziness.

- Disequilibrium is the sensation of being off balance, and is most often characterized by frequent falls in a specific direction. This condition is not often associated with nausea or vomiting.

- Presyncope is lightheadedness, muscular weakness and feeling faint as opposed to a syncope, which is actually fainting.

- Non-specific dizziness is often psychiatric in origin. It is a diagnosis of exclusion and can sometimes be brought about by hyperventilation.

A stroke is the cause of isolated dizziness in 0.7% of people who present to the emergency room.

The defining characteristic of BPT is a tilting of an infant’s head in recurrent episodes, for varying periods of time. Furthermore, the child’s trunk may bend in the same direction as the head, giving the baby an overall curved shape; this complaint is known as tortipelvis. In addition to this, the individual may also, but not necessarily, experience vomiting, pallor, ataxia, agitation, infantile migraine, unsteadiness of gait upon learning to walk, general malaise and nystagmus.

The periods in which the child’s head is tilted and other symptoms appear can last anywhere from a few minutes to a few weeks, with a frequency of anywhere from two per year to two per month.

Clinical appearance of the disease includes depression, a serous nasal discharge, and sporadically minor facial inflammation in mild form of the disease. In severe form, there is severe inflammation of one or both infraorbital sinuses with edema of the surrounding tissue. The swelling can cause closure of one eye or both of them. Intermandibular space and wattles of corks do swell as a course of the disease .

Many conditions are associated with dizziness. Dizziness can accompany certain serious events, such as a concussion or brain bleed, epilepsy and seizures (convulsions), strokes, and cases of meningitis and encephalitis. However, the most common subcategories can be broken down as follows: 40% peripheral vestibular dysfunction, 10% central nervous system lesion, 15% psychiatric disorder, 25% presyncope/disequilibrium, and 10% nonspecific dizziness. Some vestibular pathologies have symptoms that are comorbid with mental disorders. The medical conditions that often have dizziness as a symptom include:

- Benign paroxysmal positional vertigo

- Meniere's disease

- Vestibular neuronitis

- Labyrinthitis

- Otitis media

- Brain tumor

- Acoustic neuroma

- Motion sickness

- Ramsay Hunt syndrome

- Migraine

- Multiple sclerosis

- Pregnancy

- low blood pressure (hypotension)

- low blood oxygen content (hypoxemia)

- heart attack

- iron deficiency (anemia)

- low blood sugar (hypoglycemia)

- hormonal changes (e.g. thyroid disease, menstruation, pregnancy)

- panic disorder

- hyperventilation

- anxiety

- depression

- age-diminished visual, balance, and perception of spatial orientation abilities