Sudden Hearing Loss in One Ear: What Adults Need to Know

When to Act — Read This Part First

If you experienced a sudden, unexplained drop in hearing in one ear within the last 72 hours, the most important action is to see a doctor — ideally an ENT, or urgent care/the ER if an ENT isn't immediately available — as soon as possible. This isn't a "wait and see for a week" situation in the way many ear symptoms are.

The reason for urgency is specific: sudden sensorineural hearing loss (SSHL) responds significantly better to corticosteroid treatment when started within the first one to two weeks, and ideally within the first few days. Waiting reduces the odds of meaningful recovery. Even if the eventual diagnosis turns out to be something far less serious, like earwax impaction, getting evaluated quickly costs little and rules out the more time-sensitive possibilities.

What Counts as "Sudden"

Clinically, sudden hearing loss generally refers to a measurable drop in hearing occurring over less than 72 hours, though many people notice it within minutes to hours, sometimes immediately upon waking. People often describe a "pop" followed by muffled or absent hearing, fullness in the ear, or realizing during a phone call that one ear isn't picking up sound the way it normally does.

Possible Causes

Sudden Sensorineural Hearing Loss (SSHL)

The diagnosis of most concern and the reason for the urgency. SSHL involves damage to the inner ear's sensory cells or the auditory nerve, and in a substantial share of cases, no definitive single cause is ever identified — these are labeled idiopathic. Suspected contributing factors include viral infections affecting the inner ear, autoimmune processes, vascular issues affecting blood flow to the inner ear, and, less commonly, an underlying structural cause like an acoustic neuroma.

Earwax Impaction

A buildup of earwax that suddenly shifts or becomes more impacted, sometimes after water exposure causes it to swell, can produce a surprisingly sudden-feeling drop in hearing — one of the more easily and completely treatable causes.

Eustachian Tube Blockage

A sudden, significant blockage, often related to a cold, sinus infection, or rapid altitude change, can cause a fast pressure imbalance that feels like sudden hearing loss, frequently alongside fullness or pressure.

Acoustic Trauma

An extremely loud, sudden noise — gunfire, an explosion, a very loud concert speaker at close range — can cause immediate damage to inner ear structures, producing sudden hearing loss, often with ringing in the same ear.

Vascular Causes

Because the inner ear depends on a very small, specific blood supply, a disruption to that blood flow, sometimes related to a small clot or vascular event, can cause sudden hearing loss in some cases.

Cause	Typical Distinguishing Features
Sudden sensorineural hearing loss	No clear trigger, may include ringing or dizziness, requires prompt steroid treatment
Earwax impaction	Sense of fullness, sometimes after water exposure or swimming
Eustachian tube blockage	Linked to a cold, congestion, or recent flight; pressure sensation prominent
Acoustic trauma	Clear connection to a specific very loud noise event; often with ringing

What an ENT Evaluation Typically Involves

Expect a visual exam of the ear canal and eardrum to rule out wax or visible issues, a hearing test (audiogram) to measure and document the extent of loss, and in some cases blood tests or an MRI, particularly if other neurological symptoms are present. If SSHL is diagnosed or strongly suspected, treatment usually involves oral corticosteroids, and in some cases steroids injected directly into the middle ear. Neither guarantees full recovery, but outcomes are consistently better the earlier treatment begins.

What Recovery Looks Like

Recovery from SSHL varies considerably. Some people experience significant or complete recovery, particularly with prompt treatment, while others retain some permanent hearing loss despite treatment. Factors associated with a better prognosis: younger age, less severe hearing loss at diagnosis, earlier treatment, and the absence of dizziness or vertigo at onset. For permanent loss after SSHL, hearing aids are often effective, and an audiologist can determine the best option.

Why Some Cases Are Mistaken for Less Serious Problems

In its early hours, SSHL can feel remarkably similar to a clogged ear from congestion or water exposure — both produce a muffled, "underwater" sensation. The distinguishing feature: SSHL tends to be a more dramatic, often near-complete loss of hearing on that side, and it doesn't improve with yawning, swallowing, or gently popping the ears the way genuine congestion-related blockages often do. Because this distinction isn't always obvious without professional equipment, the safer approach when in doubt is still to be seen rather than wait a day or two to see if it resolves.

Risk Factors Worth Knowing About

SSHL can affect anyone and often arrives without warning, but certain factors are associated with somewhat higher reported rates in research, including cardiovascular risk factors like high blood pressure and cholesterol, diabetes, certain autoimmune conditions, and a history of recent viral infection. None of these mean SSHL is expected, but a doctor will often ask about them during evaluation.

If your hearing symptoms are a constant ring rather than a sudden drop, the urgency calculus is different — our piece on one-sided ringing with no pain covers that more common, less time-sensitive pattern. And because vascular risk factors overlap across systems, our guide on sudden blurry vision and blood sugar covers a similarly time-relevant symptom from a different organ system.