What is an ear infection?

An ear infection¹ is, as its name would suggest, an infection of the ear. Ear infections can be caused by both bacteria and viruses. They often result from different primary illnesses, such as a cold, flu, or allergy, that cause congestion and swelling of the nasal passages, throat, and Eustachian tubes.

Eustachian tubes² are narrow tubes that run from the middle of the ear to the nose and back of the upper throat. These tubes help regulate air pressure in the middle ear, refresh and circulate this air, and drain secretions.

Respiratory infections and allergies can cause swelling, inflammation, and mucus to form in the eustachian tubes, which causes blockages and fluid to accumulate in the middle ear. This fluid can become infected, and lead to an ear infection.

Because eustachian tubes in children are narrower and more horizontal, they have more difficulty draining fluids. This is why children have a higher likelihood of developing ear infections than adults.

Sometimes, ear infections are caused by water entering the ear and creating an environment in which bacteria can grow. Ear infections can also be caused by damaging the lining of the ear canal with a foreign object.

While most ear infections clear up without medical intervention, some cases of bacterial ear infections require antibiotic treatment or ear drops. There are two different types of ear infections: otitis media and otitis externa.

What is swimmer’s ear?

Otitis externa, or swimmer’s ear³, is a particular type of ear infection that forms in the outer ear canal that runs from the eardrum to the outside of the head. This condition is called swimmer’s ear because it is often caused by water remaining in the ear after swimming, creating a moist environment in which bacteria can grow.

However, swimmer’s ear can also be caused by putting cotton swabs or other objects in the ear and damaging the thin layer of skin that lines the ear canal.

Swimmer’s ear is often treated with ear drops. Treating the condition as soon as it is noticed helps prevent complications and more serious infections from arising.

What is a middle ear infection?

Middle ear infections are referred to medically as otitis media (“otitis” meaning ear infection, and “media” meaning “middle”). These infections occur in the middle ear, which is located just behind the eardrum and contains tiny vibrating bones.

Acute otitis media caused by bacterial or viral infections that form when the Eustachian tubes fail to drain excess fluid. Children are more likely than adults to get acute otitis media.

It’s important to note that there are multiple types of ear infections:

• Otitis media with effusion is swelling and effusion (fluid buildup) in the middle ear that is not caused by bacterial or viral infections. This can occur when fluid buildup persists after an ear infection has subsided or when there is a dysfunction or noninfectious blockage in the eustachian tubes.
• Chronic otitis media with effusion occurs when fluid remains in the middle ear and keeps coming back without being accompanied with a bacterial or viral infection. This makes children more susceptible to ear infections and may lead to hearing impairment.
• Chronic suppurative otitis media involves persistent drainage from the ear that won’t go away with normal treatment. This condition can cause a perforated tympanic membrane⁴ (a hole in the eardrum)

Ear infection symptoms

When it comes to ear infections, children and adults tend to exhibit different symptoms.

The onset of signs and symptoms of an ear infection is usually acute (rapid).

Symptoms in children

Common signs and symptoms of ear infections in children include:

• Ear pain (especially when lying down)
• Tugging or pulling at the ear
• Trouble sleeping
• Crying (more than usual)
• Fussiness
• Trouble hearing or responding to sounds
• Loss of balance
• Fever of 100°F (38°C) or higher
• Drainage of fluid from the ear
• Headache
• Painful changes in ear pressure when chewing, sucking, or lying down
• Loss of appetite

Sometimes, fluid can build up in the middle ear and block sounds, which can lead to temporary difficulty hearing. While it may not be immediately obvious when this happens, children might not respond to soft sounds, may need to turn up the TV to hear it, or talk louder than normal.

If your child is too young to be able to tell you that his or her ear hurts, you should look for these signs of an infection:

• Tugging at the ear
• Crying more than usual
• Drainage of fluid from the ear
• Trouble sleeping
• Difficulties with balance
• Difficulty hearing

Symptoms in adults

The common signs and symptoms of ear infections in adults can include:

• Ear pain
• Drainage of fluid from the ear
• Trouble hearing

The signs and symptoms of ear infections can indicate a number of different conditions. While it is always important to receive the proper diagnosis and treatment, these signs may indicate a more serious condition:

• Symptoms last for more than one day
• Ear pain is severe
• Symptoms are present in your child younger than 6 months old
• Your infant or toddler is sleepless or irritable after a cold, flu, or other upper respiratory infection
• You notice fluid, pus, or bloody fluid draining from the ear

Swimmer’s ear symptoms

The symptoms of swimmer’s ear are different from those of otitis media and can progress from mild to advanced if left untreated.

The signs and symptoms of swimmer’s ear begin with:

• Itching in the ear canal
• Slight redness inside the ear
• Mild discomfort that is made worse by pulling on the outer ear or pushing on the triangular tab in front of your ear (the tragus)
• Some drainage of clear, odorless fluid

Symptoms of swimmer’s ear that have reached moderate progression include:

• More intense itching
• Increased pain
• Worsened redness in the ear
• Excessive fluid drainage
• The feeling of fullness inside the ear and partial blockage of the ear canal caused by swelling, fluid, and debris
• Decreased or muffled hearing

A swimmer’s ear that has been left untreated and has reached advanced progression can include:

• Severe pain that may radiate to the face, neck, or side of the head
• Redness or swelling of the outer ear
• Complete blockage of the outer ear
• Swelling of the lymph nodes⁵ in the neck
• Fever

You should contact your healthcare provider if you or your child has even mild signs or symptoms of swimmer’s ear. As always, a healthcare provider is the best person to see if you have any symptoms of an ear infection, or if you develop new or worsened symptoms.

How do you get an ear infection?

Middle ear infections usually occur when swelling is present in one or both of the eustachian tubes.

Upper respiratory infections (like the common cold and the flu), throat infections, acid reflux⁶, and allergies⁷ can cause the eustachian tubes to swell, preventing the normal drainage of mucus or fluids from the middle ear into the throat.

When these fluids accumulate, they can harbor bacteria or viruses, creating pus that builds up in the middle ear and leading to an ear infection.

Adenoids⁸—two small pads of tissues located high up in the back of the nose—are also thought to play a role in the development of ear infections. Because they are located near the opening of the eustachian tubes, adenoids can block these tubes when they become swollen, leading to a middle ear infection.

The swelling and irritation of adenoids is most likely to contribute to ear infection in children, since children have relatively larger adenoids than adults.

Risk factors for ear infections

Some risk factors that may increase the chances of getting an ear infection or developing complications as a result of an ear infection include:

• Age: Children between the ages of 6 months and 2 years old are more susceptible to ear infections because of the size and shape of their Eustachian tubes, and because their immune systems are still developing.
• Seasonal factors: Ear infections are most common during the fall and winter—particularly because this is when cold and flu viruses are most active. People with seasonal allergies (hay fever⁹) may also have a higher risk of developing ear infections when pollen counts are high.
• Poor air quality: Exposure to tobacco smoke or significant air pollution can increase the risk of developing an ear infection.
• Group childcare: Children that spend time in group care settings are more likely to be exposed to infections like colds—and, as a result, develop ear infections—than children who stay at home.
• Infant feeding: Breast milk contains immunoglobulins (specifically IgA), which cannot be replicated in infant formula. Babies are born with low IgA and, when breastfed, receive antibodies and develop immune protection. This lowers their risk of contracting infections, including acute otitis media.
• Alaskan Native heritage: Ear infections are more common among people of Alaskan Native heritage.
• Cleft palate: Differences in the bone structure and muscles of children with cleft palates¹⁰ may make it more difficult for eustachian tubes to drain.

Complications from ear infections

Most ear infections go away without medical intervention and do not cause serious, long-term complications.

However, ear infections that happen over and over (chronic otitis media¹¹) can lead to complications, including:

• Hearing loss or impairment: While mild, temporary hearing loss is common with ear infections (and generally goes away when the infection does), chronic ear infections or the accumulation of fluid in the middle ear can lead to more significant hearing loss. Permanent hearing loss can occur when there is irreversible damage done to the eardrum or other middle ear structures.
• Speech or developmental delays: Infants and toddlers may experience delays in speech and social and developmental skills if hearing is temporarily or permanently impaired.
• Spread of infection: Untreated infections or infections that don’t respond well to treatment can spread to nearby tissues and structures. One such infection, called mastoiditis, is an infection of the mastoid (the bony protrusion behind the ear). This infection can cause damage to the bone and the formation of pus-filled cysts. Rarely, serious middle ear infections will spread to other tissues in the skull, including the brain or the membranes surrounding the brain and spinal cord (meningitis¹²).
• Tearing of the eardrum: While most eardrums heal within 72 hours, in some cases, surgical repair is necessary.

How do you get swimmer’s ear?

Swimmer’s ear is an infection usually caused by bacteria (less commonly, swimmer’s ear can be caused by a fungus or virus).

Your outer ear canals have a number of natural defenses in place that help to keep them clean and prevent the development of infection. There are glands in the ear that secrete a waxy substance called cerumen that forms a thin, water-repellent layer on the skin inside the ear. Cerumen is also highly acidic, which helps inhibit the growth of bacteria, and collects and moves dirt, dead skin cells, and other debris out of the ear canal. There is also cartilage in the ear that partly covers the ear canal, helping to block foreign bodies from entering the canal.

Swimmer’s ear occurs when your ear’s natural defense mechanisms have been overwhelmed. Some conditions that can weaken these defenses and promote the growth of bacteria include:

• Excess moisture in the ear (from heavy perspiration, prolonged humid weather, or water remaining in the ear after swimming)
• Scratches or abrasions in the ear canal caused by cleaning the canal with a cotton swab, scratching the inside of your ear with your finger, or wearing earbuds or hearing aids
• Sensitivity or allergic reactions (caused by irritants like hair products or jewelry) that promote infections

Risk factors for swimmer’s ear

Some risk factors that may increase the chances of getting swimmer’s ear or developing complications as a result of swimmer’s ear include:

• Swimming
• Getting water with high bacteria content into the ear
• Aggressive cleaning of the ear canal with cotton swabs or other objects
• Wearing certain in-ear devices like earbuds or hearing aids
• Skin allergies or irritation from jewelry, hair spray, or hair dyes

Complications from swimmer’s ear

If treated right away, swimmer’s ear usually isn’t serious. However, some complications can occur if the condition is left untreated, including:

• Temporary hearing loss
• Long-term infection (chronic otitis externa¹³)
• Deep tissue infection (cellulitis¹⁴)
• Bone and cartilage damage (early skull base osteomyelitis¹⁵)
• Widespread infection to nearby tissues, structures, or nerves