The incidence of otitis externa is high. In the Netherlands, it has been estimated at 12–14 per 1000 population per year, and has been shown to affect more than 1% of a sample of the population in the United Kingdom over a 12-month period.

Swimming in polluted water is a common way to contract swimmer's ear, but it is also possible to contract swimmer's ear from water trapped in the ear canal after a shower, especially in a humid climate. Constriction of the ear canal from bone growth (Surfer's ear) can trap debris leading to infection. Saturation divers have reported Otitis externa during occupational exposure.

Long-term antibiotics, while they decrease rates of infection during treatment, have an unknown effect on long-term outcomes such as hearing loss. This method of prevention has been associated with emergence of antibiotic-resistant otitic bacteria. They are thus not recommended.

Pneumococcal conjugate vaccines (PCV) in early infancy, decreases the risk of acute otitis media in healthy infants. PCV is recommended for all children, and, if implemented broadly, PCV would have a significant public health benefit. Influenza vaccine is recommended annually for all children. PCV does not appear to decrease the risk of otitis media when given to high-risk infants or for older children who have previously experienced otitis media.

Risk factors such as season, allergy predisposition and presence of older siblings are known to be determinants of recurrent otitis media and persistent middle-ear effusions (MEE). History of recurrence, environmental exposure to tobacco smoke, use of daycare, and lack of breastfeeding have all been associated with increased risk of development, recurrence, and persistent MEE. Thus, cessation of smoking in the home should be encouraged, daycare attendance should be avoided or daycare facilities with the fewest attendees should be recommended, and breastfeeding should be promoted.

There is some evidence that breastfeeding for the first year of life is associated with a reduction in the number and duration of OM infections. Pacifier use, on the other hand, has been associated with more frequent episodes of AOM.

Evidence does not support zinc supplementation as an effort to reduce otitis rates except maybe in those with severe malnutrition such as marasmus.

Adhesive otitis media occurs when a thin retracted ear drum becomes sucked into the middle-ear space and stuck (i.e., adherent) to the ossicles and other bones of the middle ear.

In the United States and other developed countries, the incidence of mastoiditis is quite low, around 0.004%, although it is higher in developing countries. The condition most commonly affects children aged from two to thirteen months, when ear infections most commonly occur. Males and females are equally affected.

Adenoiditis occurs mainly in childhood, often associated with acute tonsillitis. Incidence decreases with age, with adenoiditis being rare in children over 15 years due to physiological atrophy of the adenoid tissue.

With prompt treatment, it is possible to cure mastoiditis. Seeking medical care early is important. However, it is difficult for antibiotics to penetrate to the interior of the mastoid process and so it may not be easy to cure the infection; it also may recur. Mastoiditis has many possible complications, all connected to the infection spreading to surrounding structures. Hearing loss is likely, or inflammation of the labyrinth of the inner ear (labyrinthitis) may occur, producing vertigo and an ear ringing may develop along with the hearing loss, making it more difficult to communicate. The infection may also spread to the facial nerve (cranial nerve VII), causing facial-nerve palsy, producing weakness or paralysis of some muscles of facial expression, on the same side of the face. Other complications include Bezold's abscess, an abscess (a collection of pus surrounded by inflamed tissue) behind the sternocleidomastoid muscle in the neck, or a subperiosteal abscess, between the periosteum and mastoid bone (resulting in the typical appearance of a protruding ear). Serious complications result if the infection spreads to the brain. These include meningitis (inflammation of the protective membranes surrounding the brain), epidural abscess (abscess between the skull and outer membrane of the brain), dural venous thrombophlebitis (inflammation of the venous structures of the brain), or brain abscess.

Pharyngitis may also be caused by mechanical, chemical or thermal irritation, for example cold air or acid reflux. Some medications may produce pharyngitis such as pramipexole and antipsychotics.

Some cases of pharyngitis are caused by fungal infection such as Candida albicans causing oral thrush.

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.

It is currently believed that bacterial biofilms play an integral role in the harboring of chronic infection by tonsil and adenoid tissue so contributing to recurrent sinusitis and recurrent or persistent ear disease. Also, enlarged adenoids and tonsils may lead to the obstruction of the breathing patterns in children, causing apnea during sleep.

The most common bacteria isolated are Haemophilus influenzae, group A beta-hemolytic Streptococcus, Staphylococcus aureus, Moraxella catarrhalis, and Streptococcus pneumoniea. Heamophilus influenza, Moraxella catarrhalis and Streptococcus pneumonia are the three most resistant pathogens of otitis and rhinosinisitis in children suffering from these diseases.

Otitis media is a particularly common cause of otalgia in early childhood, often occurring secondary to other infectious illnesses, such as colds, coughs, or conjunctivitis.

It has been hypothesized that biofilm bacterial infections may account for many cases of antibiotic-refractory chronic sinusitis. Biofilms are complex aggregates of extracellular matrix and inter-dependent microorganisms from multiple species, many of which may be difficult or impossible to isolate using standard clinical laboratory techniques. Bacteria found in biofilms have their antibiotic resistance increased up to 1000 times when compared to free-living bacteria of the same species. A recent study found that biofilms were present on the mucosa of 75% of people undergoing surgery for chronic sinusitis.

Sinusitis is a common condition, with between 24 and 31 million cases occurring in the United States annually. Chronic sinusitis affects approximately 12.5% of people.

Laryngitis that continues for more than three weeks is considered chronic. If laryngeal symptoms last for more than three weeks, a referral should be made for further examination, including direct laryngoscopy. The prognosis for chronic laryngitis varies depending on the cause of the laryngitis.

It is normally possible to establish the cause of ear pain based on the history. It is important to exclude cancer where appropriate, particularly with unilateral otalgia in an adult who uses tobacco or alcohol.Often migraines are caused by middle ear infections which can easily be treated with antibiotics. Often using a hot washcloth can temporarily relieve ear pain.

In one study, the number of new cases of cholesteatoma in Iowa was estimated in 1975–6 to be just under one new case per 10,000 citizens per year. Cholesteatoma affects all age groups, from infants through to the elderly. The peak incidence occurs in the second decade.

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

Acute laryngitis may persist, but will typically resolve on its own within two weeks. Recovery is likely to be quick if the patient follows the treatment plan. In viral laryngitis, symptoms can persist for an extended amount of time, even when upper respiratory tract inflammation has been resolved.

Otomycosis is treated by debridment followed with topical azole antifungals, and symptomatically managed with oral antihistamines. Per a study in Iran 10cc acetic acid 2% plus 90 cc of isopropyl alcohol 70% was effective.

"Acute bacterial parotitis:"

is most often caused by a bacterial infection of Staphylococcus aureus but may be caused by any commensal bacteria.

"Parotitis as Extrapulmonary Tuberculosis:"

The mycobacterium that cause tuberculosis can also cause parotid infection. Those infected tend to have enlarged, nontender, but moderately painful glands. The diagnosis is made by typical chest radiograph findings, cultures, or histologic diagnosis after the gland has been removed. When diagnosed and treated with antitubercular medications, the gland may return to normal in 1–3 months.

"Acute viral parotitis (mumps):"

The most common viral cause of parotitis is mumps. Routine vaccinations have dropped the incidence of mumps to a very low level. Mumps resolves on its own in about ten days.

"HIV parotitis:" Generalized lymphadenopathy has long been associated with HIV, but the localized enlargement of the parotid gland is less well known.

It is important that the patient attend periodic follow-up checks, because even after careful microscopic surgical removal, cholesteatomas may recur. Such recurrence may arise many years, or even decades, after treatment.

A "residual cholesteatoma" may develop if the initial surgery failed to completely remove the original; residual cholesteatomas typically become evident within the first few years after the initial surgery.

A "recurrent cholesteatoma" is a new cholesteatoma that develops when the underlying causes of the initial cholesteatoma are still present. Such causes can include, for example, poor eustachian tube function, which results in retraction of the ear drum, and failure of the normal outward migration of skin.

In a retrospective study of 345 patients with middle ear cholesteatoma operated on by the same surgeon, the overall 5-year recurrence rate was 11.8%. In a different study with a mean follow-up period of 7.3 years, the recurrence rate was 12.3%, with the recurrence rate being higher in children than in adults.

Headgear called a "scrum cap" in rugby, or simply "headgear" or earguard in wrestling and other martial arts, that protects the ears is worn to help prevent this condition. For some athletes, however, a cauliflower ear is considered a badge of courage or experience.

Ear eczema is an eczema of the ear that may involve the helix, postauricular fold, and external auditory canal, with the most frequently affected site being the external canal, where it is often a manifestation of seborrheic dermatitis or allergic contact dermatitis.

These are also collectively known as chronic punctate parotitis or chronic autoimmune parotitis.

"Sjögren's syndrome:"

Chronic inflammation of the salivary glands may also be an autoimmune disease known as Sjögren's syndrome. The disease most commonly appears in people aged 40–60 years, but it may affect small children. In Sjögren syndrome, the prevalence of parotitis in women versus men is approximately 9:1. The involved parotid gland is enlarged and tender at times. The cause is unknown. The syndrome is often characterized by excessive dryness in the eyes, mouth, nose, vagina, and skin.

"Lymphoepithelial lesion of Godwin:"

Most frequently associated with a circumscribed tumor with the histologic features of Sjögren syndrome. This designation has also fallen out of favour.