What Causes Ear Infections in Adults?

2 Main Types of Ear Infections

Illustration by Joshua Seong. © Verywell, 2017.

Did you think that ear infections would be over once you entered adulthood? Compared to children, you are less likely to get an ear infection due to the anatomical difference in the shape and size of the eustachian tube, the tube that runs from the middle ear to the back of your throat.

However, while ear infections predominantly occur in children, you may still experience an ear infection as an adult—less than 20 percent of all treated ear infections occur in adults.

Ear infections are usually referring to a middle ear infection (otitis media), however, you may also hear the term in relation to outer ear infections, otitis externa or swimmer's ear, as well.

Risk Factors for Middle Ear Infections

While eustachian tube dysfunction is more common in children, poor tubal function can persist into adulthood and is the main cause for middle ear infections in adults. When the eustachian tube doesn't function normally, fluid or bacteria become trapped inside the ear from and cause an infection.

These common disorders could cause adults to have eustachian tube dysfunction and be more prone to ear infections:

  • Weakened immune system

The factors listed above increase your risk for acquiring an ear infection because of the effects that the risk factor has on your eustachian tube. A eustachian tube that is dysfunctional does not allow for proper drainage of fluid in your middle ear and can make you susceptible to an ear infection.

Symptoms of Adult Ear Infections

Many of the risk factors listed above will predispose you to experiencing recurrent and chronic ear infections. Understanding what is predisposing you to them will help your doctor more effectively treat you. In comparison to children, adults are more likely to have symptoms like otalgia (ear pain)ear drainagehearing loss, and a sore throat.

Other symptoms that are non-specific to ear infections in adults include:

Ear infections can be very bothersome and may be worrisome to you. Rest assured these symptoms can be easily treated by a skilled physician and are reversible with treatment.

Diagnosing an Ear Infection

If you had recurrent ear infections as a child, which continues into adulthood, you likely have complications related to eustachian tube dysfunction. However if you are experiencing new onset middle ear infection, your physician should complete a full head and neck physical exam. As part of the exam, your physician may perform a nasopharyngoscopy, where they will place a small fiberoptic scope up your nose to further examine the condition of your nasal passages, soft palate, and throat.

Typically the fiberoptic scope is not painful, but you may experience some discomfort, as the nose is a sensitive area. It may cause your eyes to water as the scope reaches the back of your nasal passages. While utilizing similar equipment that is used in examining your stomach, you will not need to be sedated at all for this procedure.

The standard method for diagnosing an ear infection involves examining your ear with an otoscope. When you have an ear infection, your tympanic membrane will appear red, cloudy, and bulging. To improve diagnosis, your doctor can also apply pneumatic pressure, with a pneumatic otoscope.

The tympanic membrane will have poor mobility in the setting of an ear infection. If you have fluid behind your tympanic membrane, then your tympanic membrane will appear cloudy, yellow, and will not appear see-through.

Your physician may also take the opportunity to assess how much hearing loss you are experiencing with the tuning fork test. If you are experiencing conductive hearing loss related to the infection, the sound made by the tuning fork (placed in the middle of your forehead) will be louder in the affected ear.

Treatment for Middle Ear Infections in Adults

Oral antibiotics are the treatment of choice for middle ear infections in adults. Most commonly, you will be prescribed amoxicillin ranging in doses from 250mg every 8 hours to 2g every 8 hours, depending upon the severity of your symptoms and treatment history in your area. Amoxicillin is a highly effective choice, unless your ear infection is caused by a virus, and is ineffective in only 1 out of every 10 cases.

If you have allergies to penicillin, you should avoid amoxicillin. In this case, your doctor will likely prescribe a macrolide antibiotic (like azithromycin or erythromycin) or a cephalosporin antibiotic (like cefdinir, cefuroxime). If you continue to have symptoms after a full first course of antibiotics, initial treatment will be considered as failed and your treatment will be escalated if symptoms and assessment are still consistent with a middle ear infection. In this case, you will likely be prescribed amoxicillin/clavulanate, cefuroxime, or ceftriaxone.

What If My Ear Infections Are Persistent?

If you are diagnosed with persistent middle ear infection after several treatments, your doctor will likely prescribe you a third antibiotic, clindamycin, and evaluate you for surgery to have ear tubes placed. If you have a ruptured ear drum or ear tubes, your doctor may also prescribe you ear drops like Ciprodex (ciprofloxacin and dexamethasone), which contains an antibiotic and a corticosteroid. While ear drops like Ciprodex can be very effective, you should avoid ear drops that can harm your hearing like Vosol (neomycin) or alcohol.

If you have recurrent ear infections, you doctor may also have you get a CT scan or MRI to identify causes that may be impacting your eustachian tube function. Enlarged structures in the ear or throat, such as tiny bones inside of the nose, enlarged adenoids, or nasal polyps may have to be surgically removed or reduced in size. Other methods that you can use to prevent future infections include:

  • Avoid cigarette smoke
  • Take a decongestant when you have a cold or before getting on an airplane
  • Avoid trying to clean your ear wax using Q-tips or other objects

Complications From an Untreated Ear Infection

Like many infections, not receiving treatment for an ear infection can result in some complications. A common complication that may occur, even with initial treatment, is a ruptured ear drum. Other complications may include:

Untreated ear infections do not immediately cause these complications. However, if you are experiencing frequent ear infections, or do not seek help after experiencing long-term symptoms of an ear infection, the above conditions may result. Seeking care from an ENT will help prevent these long-term complications from ever occurring.

Otitis Externa (Swimmer's Ear) in Adults

Outer ear infections are also known as swimmer's ear because they are commonly seen in swimmers. This infection occurs when contaminated water enters the outer ear, allowing germs to grow and thrive due to warm and moist conditions. Symptoms of swimmer's ear include:

  • Ear redness or itchiness inside the ear
  • Flaking of the skin on the ear
  • Drainage from the ear, which may be pus
  • Pain when moving the head or touching the ear
  • Fever

Swimmer's ear is fairly easy to diagnose and usually treated with antibiotic ear drops like Ciprodex. Sometimes pus and debris will need to be cleaned out by your physician. You can prevent swimmer's ear by:

  • Using ear plugs before swimming or bathing
  • Gently drying your ears with a blow dryer on the lowest setting after swimming or bathing
  • NOT inserting objects in the ears
  • NOT swimming in polluted water

A Word From Verywell

Chronic ear infections can greatly impact your quality of life and can be very discouraging as a child or adult. A general physician can easily treat isolated cases of ear infections as an adult. However, if you are experiencing frequent ear infections as an adult, seeking the help of an ear, nose and throat specialist will help you identify the underlying problem. Seeking help sooner will help prevent complications and help improve your quality of life.


CDC. Swimmer's Ear (Otitis Externa).

Limb, CJ, Lustig, LR & Klein JO. Acute otitis media in adults (suppurative and serous). 2017.

Ramakrishnan, K, Sparks, RA & Berryhill, WE. Diagnosis and Treatment of Otitis Media. 2007. Am Fam Physician. 76(11):1650-1658.