by Brian Hendricks, DO September 21, 2025
Sudden hearing loss, also known as sudden sensorineural hearing loss (SSNHL), is a rapid and unexplained loss of hearing, typically occurring in one ear. It can happen instantly or over the course of several hours to a few days. While it may be alarming, many people mistakenly delay treatment, assuming it will resolve on its own. However, sudden hearing loss is a medical emergency, and early intervention can significantly improve outcomes.
What Is Sudden Sensorineural Hearing Loss?
SSNHL is defined as a hearing reduction of 30 decibels or more over at least three consecutive frequencies, occurring within 72 hours or less. It usually affects only one ear and often appears upon waking or is noticed when using the phone or listening in noisy environments.
Unlike conductive hearing loss (caused by blockages like earwax or fluid), SSNHL results from issues in the inner ear cochlea or auditory nerve.
Symptoms
The hallmark symptom is sudden deafness in one ear. However, people may also experience:
- A feeling of fullness or pressure in the affected ear
- Tinnitus (ringing or buzzing in the ear)
- Dizziness or balance issues
- Difficulty understanding speech, especially in noisy environments
- Sound distortion
These symptoms may occur alone or in combination.
Causes
In most cases (up to 90%), the exact cause of SSNHL is unknown and classified as idiopathic. However, potential causes include:
- Viral infections (e.g., a cold or flu affecting the inner ear)
- Circulatory problems (interrupted blood flow to the ear)
- Autoimmune disorders (the body attacking inner ear cells)
- Trauma (head injury or barotrauma from pressure changes)
- Neurological disorders (like multiple sclerosis)
- Tumors (such as acoustic neuroma—rare but serious)
- Ototoxic medications (drugs that damage inner ear structures)
Diagnosis
If you experience sudden hearing loss, seek medical attention immediately—preferably from an ear, nose and throat (ENT) specialist.
Diagnosis typically involves:
- Hearing tests (audiometry) to determine the type and degree of hearing loss
- Physical exam of the ear
- MRI scan to rule out tumors or neurological causes
- Blood tests to check for autoimmune, viral or vascular conditions
Treatment
Early treatment—ideally within 72 hours of onset—is crucial.
Common treatments include:
- Corticosteroids (oral or injected): Reduce inflammation and improve chances of hearing recovery
- Antiviral medications: If a viral infection is suspected
- Hyperbaric oxygen therapy: Increases oxygen supply to the inner ear (used in some cases)
- Treating underlying conditions: Such as autoimmune diseases or circulatory problems
In cases where hearing does not return, hearing aids or cochlear implants may be recommended to restore some level of hearing.
Prognosis
About 1 in 3 people recover fully, another third experience partial improvement, and the rest may have permanent hearing loss. The outcome often depends on:
- How quickly treatment was started
- Severity of the hearing loss
- Presence of symptoms like vertigo (which may indicate a poorer prognosis)
When to See a Doctor
You should seek emergency medical care if you experience:
- Sudden hearing loss in one ear
- Hearing that fades over a few hours or days
- Tinnitus, dizziness or a feeling of fullness in the ear
Do not wait to see if the problem goes away—early evaluation and treatment are essential.
Conclusion
Sudden hearing loss can be frightening, but it’s important to treat it as a medical emergency. Prompt diagnosis and early treatment significantly improve the chances of recovery. Whether it’s a viral infection, circulation issue or an unknown cause, getting help quickly is the key to protecting your hearing health.
