Bottom line: If hearing in one ear suddenly becomes muffled, quieter, or distorted, do not assume it is earwax, congestion, or an allergy and wait several days. A blocked ear canal or middle-ear problem is possible, but sudden sensorineural hearing loss (SSNHL) is an inner-ear emergency that needs prompt assessment. Contact a service that can examine the ear and arrange hearing testing, ideally the same day symptoms begin.
Who is this guidance for?
This applies to adults whose hearing changes suddenly over hours or up to about three days in one or both ears. You may wake with one ear feeling blocked, notice that a phone sounds much quieter on one side, or find familiar sounds distorted or distant. Tinnitus, ear fullness, dizziness, or vertigo may occur with the hearing change.
Congestion, fluid behind the eardrum, and earwax can also reduce hearing. Their presence does not prove that the inner ear is unaffected. Conductive and sensorineural hearing loss require different evaluation, and they cannot be reliably separated by cleaning the ear or waiting at home.
Why is sudden hearing loss urgent?
The U.S. National Institute on Deafness and Other Communication Disorders (NIDCD) describes sudden sensorineural hearing loss as a medical emergency and advises immediate medical care. Some people recover partly or fully without treatment, but delaying diagnosis and treatment when it is indicated can reduce effectiveness.
A commonly used audiometric definition is a drop of at least 30 decibels across three consecutive frequencies within 72 hours. You cannot determine this threshold at home, and more subtle sudden changes can still be clinically important. Being able to hear some sound does not make it safe to postpone assessment.
How do clinicians distinguish earwax from inner-ear hearing loss?
Earwax, middle-ear fluid, and some infections cause conductive hearing loss by blocking sound transmission. SSNHL involves the cochlea or auditory nerve. Both can feel like fullness or muffled hearing.
A clinician examines the ear canal and eardrum and uses hearing tests—typically pure-tone audiometry and often speech testing—to identify the type and degree of loss. If sensorineural loss is confirmed, the history and examination may lead to blood tests, balance testing, or MRI to look for an underlying cause, including a problem along the hearing nerve.
How do care pathways differ by country?
In the United States, urgent access may be through an otolaryngologist, urgent eye-and-ear or ENT service, urgent care, or an emergency department, depending on local availability and insurance. Tell the service that this is “sudden hearing loss in one ear,” not a routine long-standing hearing problem.
In the United Kingdom, NICE recommends immediate referral—to be seen within 24 hours—for hearing loss that developed over three days or less within the past 30 days when it is not explained by an outer- or middle-ear cause. In Korea, contacting an ENT clinic with audiometry on the same day is a practical first route; emergency care is appropriate when timely ENT access is unavailable or neurologic or trauma warning signs are present.
What should you know about treatment?
Corticosteroids are commonly considered for idiopathic SSNHL and may be given by mouth or by injection through the eardrum. The choice depends on timing, hearing-test results, diabetes, glaucoma, infection risk, gastrointestinal history, and other medicines. Do not use leftover steroids or another person’s prescription.
It is also not appropriate to wait for every possible test before asking about treatment timing, or to demand one treatment based only on an online article. Ask the treating clinician about expected benefits, adverse effects, alternatives, and the useful treatment window for your circumstances.
When should you seek emergency help now?
- sudden hearing loss with facial droop, weakness or numbness on one side, or trouble speaking;
- a new severe headache, double vision, or inability to walk normally;
- hearing loss after a head injury, explosion, or extremely loud noise;
- sudden loss in both ears or rapidly worsening symptoms; or
- severe vertigo and vomiting, fainting, confusion, or another major neurologic change.
These features can point to stroke, trauma, neurologic disease, or another emergency and should not wait for a routine clinic appointment.
What to record and ask at the visit
- Record the exact start time, which ear is affected, and whether the change happened at once or progressed over a few days.
- Note tinnitus, fullness, vertigo, ear pain or discharge, recent infection, injury, loud-noise exposure, and any new medicine.
- Ask: “Is this conductive or sensorineural hearing loss?”, “Do I need audiometry today?”, “Which additional tests or treatment decisions are time-sensitive?”, and “Which new symptoms mean I should go to the emergency department?”
Related Life Choice Note resources
- Symptom timeline and visit questions
- Medication and supplement list
- Health records and visit preparation
Sources and review date
- National Institute on Deafness and Other Communication Disorders: Sudden Deafness
- American Academy of Otolaryngology–Head and Neck Surgery: Sudden Hearing Loss Guideline
- NICE: Hearing Loss in Adults—Recommendations
- NHS: Hearing Loss
- Korea National Health Insurance Service: Sudden Hearing Loss
Reviewed October 3, 2026. General health information only, not individual diagnosis or treatment. This page does not claim independent medical review.