Otosclerosis is a condition of the middle ear that involves abnormal bone remodeling. Otosclerosis causes tissues to harden around three bones called the stapes, incus, and malleus.

Bone remodeling typically involves the natural turnover and regrowth of bone tissues.

The abnormal bone remodeling that occurs with otosclerosis — also known as otospongiosis — can lead to hearing loss. This is because sound may not be able to travel from your middle to the inner ear due to the inflexibility of the stapes that would normally support this process.

The exact cause is unknown, but early detection of otosclerosis is key to helping you access treatments that can improve your hearing.

It’s estimated that at least 3 million people in the U.S. have otosclerosis. You may consider discussing possible symptoms with a doctor as a starting point.

A note on sex and gender

Sex and gender exist on spectrums. This article will sometimes use the terms “male,” “female,” or both to refer to sex assigned at birth in order to reflect the language of our sources. Learn more about sex and gender.

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While there are a number of conditions that may lead to hearing issues, otosclerosis primarily causes gradual hearing loss. Consider the possible symptoms you may further discuss with a doctor:

  • Gradual hearing loss: As the most common symptom of otosclerosis, hearing loss may start off as minimal, but then gets worse over the course of several years.
  • Inability to hear certain sounds: When otosclerosis first develops, you may find that you have a hard time hearing whispers or low-pitched sounds.
  • Hearing loss that starts in one ear: Typically, it begins in one ear first, and then develops in the other ear.
  • Extent of hearing loss varies in each ear: While 70% of people with otosclerosis have hearing loss in both ears, the amount of hearing loss usually differs in each.
  • Tinnitus: Along with hearing loss, some people with otosclerosis might experience symptoms of tinnitus, including sudden ringing or buzzing in the ears.
  • Vertigo: In addition to ear symptoms, some people also experience problems with balance, as well as dizziness when they have otosclerosis.

Between 2.5 to 10% of all adults are thought to have otosclerosis.

While certain types of infections, immune-mediated diseases, and stress fractures may be possible risk factors for developing otosclerosis, the exact cause of this ear condition isn’t clear. Scientists believe that otosclerosis may run in families.

The average age of onset for otosclerosis is between 30 and 50 years of age, with hearing loss beginning in your 20s. It’s uncommon for children to develop this condition.

Also, white, middle-aged women are thought to be at higher risk.

There’s also a theory and anecdotal reporting that pregnancy may increase the risk of otosclerosis. In fact, a 2020 review found that females with a higher number of children needed surgery of the stapes at a younger age overall.

But the authors also note that there’s not enough evidence to draw a definitive link between pregnancy and otosclerosis. It’s also possible that hormone fluctuations in pregnancy could worsen pre-existing cases.

When left untreated, otosclerosis may lead to significant hearing loss. This can make it difficult to participate in your everyday activities.

But complete hearing loss from otosclerosis is considered rare.

Another rare complication is worsened hearing loss as a result of surgical treatment for otosclerosis. Tinnitus and facial nerve damage are also possible.

If you’re experiencing any amount of hearing loss or auditory discomfort, you might consider seeing a doctor for help. They may refer you to a specialist called an otolaryngologist, also known as an ear, nose, and throat doctor (ENT).

An ENT can help diagnose otosclerosis based on the following:

  • a history of your symptoms, including when they began and their severity
  • a physical examination of your ears
  • hearing tests performed by an audiologist
  • imaging scans of your middle ears to assess damage to the stapes

Treatment for otosclerosis depends on the extent of hearing loss. In cases where hearing loss is mild, an ENT may recommend a wait-and-see approach along with regular hearing tests.

Hearing aids may be another option if your hearing loss is milder. Cochlear implants may also be considered if you have more advanced hearing loss from otosclerosis.

Severe hearing loss may also be treated with a surgery called a stapedectomy, which involves removing the stapes and replacing them with a prosthetic device to help improve your hearing. Surgery is thought to help improve otosclerosis in 90% of cases.

Gradual hearing loss is a common sign of otosclerosis, which most often develops in early to middle adulthood. Tinnitus and vertigo are also possible.

If you think you may have symptoms of otosclerosis or are experiencing problems with your hearing more generally, it’s important to talk with a doctor. They can direct you to the right treatments once they determine the underlying cause of your hearing loss.