Sudden Hearing Loss: What Causes It and Why Treatment Can't Wait

You wake up one morning and your left ear feels blocked, like you're underwater. You assume it's earwax or congestion from a cold. By afternoon, you realize you can barely hear conversations on that side. By evening, you're worried—but unsure if this warrants urgent medical attention.

This scenario describes sudden sensorineural hearing loss (SSHL/SSNHL)—a medical condition affecting about 5–27 people per 100,000 each year in the United States (roughly 66,000 new cases annually). What makes sudden hearing loss different from gradual hearing changes is both the speed of onset and the treatment window: there's a narrow period when intervention works best.

What Is Sudden Sensorineural Hearing Loss?

Sudden sensorineural hearing loss is defined as hearing loss of at least 30 decibels across three consecutive frequencies on a hearing test, developing within 72 hours or less. To put 30 decibels in perspective, that's roughly the difference between a whisper and normal conversation volume.

Most commonly, sudden hearing loss affects just one ear. Rarely, both ears are involved. People often first notice it upon waking, when trying to use a phone, or during activities requiring that ear.

What Causes Sudden Hearing Loss?

Here's what makes sudden hearing loss particularly challenging: in most cases, we never identify a single definite cause. These are labeled "idiopathic" sudden hearing loss. However, research suggests several possible mechanisms and, in a smaller number of cases, an underlying condition can be identified.

Viral Infections

Viral infection is a possible cause of sudden hearing loss, but we usually can’t prove it. About 1 in 4 people report a recent cold before symptoms, which may be related but doesn’t confirm the virus caused the hearing change.

Vascular Problems

The inner ear is sensitive to changes in blood flow, so circulation problems are one suspected mechanism for sudden hearing loss in some people. Risk factors like diabetes, hypertension, smoking, or clotting disorders may raise concern for vascular contributions.

Benign Tumor on the Hearing/Balance Nerve (Vestibular Schwannoma / “Acoustic Neuroma”)

Very rarely, sudden hearing loss is due to a benign (non-cancerous) tumor on the nerve that connects the ear to the brain. This is one reason clinicians may recommend an MRI as part of the evaluation.

Autoimmune Conditions

In some cases, the immune system can mistakenly target the inner ear, leading to rapid hearing changes. Clues may include hearing changes in both ears, other autoimmune symptoms, or certain blood test findings.

Inner Ear Disorders

Some inner ear conditions can cause sudden or rapidly changing hearing, sometimes along with vertigo (spinning) or ear pressure/fullness.

Medications and Other Exposures

Certain medications (including some used for cancer treatment or serious infections) can affect inner ear function. Your clinician will review your medication list and recent exposures.

Neurologic Causes

Less commonly, sudden hearing changes may be related to neurologic conditions. Symptoms like weakness, facial droop, severe imbalance, new numbness, or trouble speaking should be treated as urgent warning signs.

Head Trauma

Head injury can sometimes cause sudden hearing loss and related ear symptoms.

Why Treatment Timing Matters

This is the critical piece of information about sudden hearing loss: earlier evaluation and treatment offer the best chance of recovery. Steroids are most effective when started as soon as possible, and initial treatment is generally most helpful when started within the first 2 weeks. Treatment started more than 2–4 weeks after onset is less likely to reverse or reduce permanent hearing loss.

What Treatment Looks Like

The standard treatment for sudden hearing loss involves corticosteroids, which reduce inflammation in the inner ear. Treatment approaches include:

Oral Steroids

Typically a high dose of prednisone for 1–2 weeks, often using a "blast and taper" approach.

Intratympanic Steroid Injections

If oral steroids are ineffective or medically unsafe for you, clinicians may inject steroids directly through the eardrum into the middle ear space. This delivers high concentrations of medication close to the inner ear.

What Recovery Looks Like

Recovery varies widely—from a full return of hearing to little change. About half of people recover some or all hearing on their own, often within 1–2 weeks. Because treatment is most effective when started early, contact a clinician right away if your hearing changes suddenly.

Factors linked with better recovery: milder hearing loss at the start, no vertigo (spinning), and younger age. Starting steroid treatment within the first week is associated with better odds of full recovery, and treatment is generally most helpful when started within the first 2 weeks.

References

• AAO-HNSF. Sudden Hearing Loss: Update to Guideline to Improve Implementation and Awareness (2019). View
• AAO-HNSF. Sudden Sensorineural Hearing Loss (SSNHL) Frequently Asked Questions (patient handout). View PDF
• NIDCD (NIH). Sudden Deafness (fact sheet). View PDF
• AAO-HNSF. Clinical Practice Guideline: Sudden Hearing Loss (Update) (guideline hub page). View
• Mandavia R, Joshi N, Hannink G, et al. A Prognostic Model to Predict Hearing Recovery in Patients With Idiopathic Sudden Onset Sensorineural Hearing Loss. JAMA Otolaryngology–Head & Neck Surgery (2024). View

Common Questions About Sudden Hearing Loss

How do I know if my hearing loss needs urgent attention?

Seek urgent evaluation immediately if you notice a sudden drop in hearing (over hours to up to 3 days), especially in one ear. Symptoms like ear fullness/pressure, tinnitus (ringing), or dizziness can happen too. If you also have neurologic symptoms (new weakness, facial droop, trouble speaking, severe imbalance), go to the ER.

Can I wait to see if it gets better on its own?

It’s best not to wait. Some people recover on their own, but delaying diagnosis and treatment can reduce treatment effectiveness. Steroid treatment works best when started as soon as possible and is generally most helpful when started within the first 2 weeks.

Should I get an MRI right away?

Not necessarily immediately—treatment shouldn’t wait for imaging. An MRI (or ABR in some cases) is often recommended as part of the evaluation to rule out rare causes like vestibular schwannoma (acoustic neuroma) and other structural problems.

Experiencing Sudden Hearing Changes?

If you're experiencing sudden hearing loss, our emergency care guide explains when and where to seek help, what to expect during evaluation, and how to access urgent appointments.

View Emergency Care Guide