Sudden hearing loss: a case-based approach

The presentation

A 52-year-old office worker we will call "David" (an illustrative example) wakes on a Monday and notices the world sounds lopsided. His right ear feels full and muffled, as if underwater, and there is a constant high-pitched ringing in it. When his phone rings on that side he can barely make out the caller. He has no pain, no discharge and no recent cold. He assumes it will clear, but by Wednesday it is no better. This picture — a sudden, one-sided loss of hearing with ringing and a blocked feeling, but no pain or infection — is exactly the pattern that should prompt urgent ENT assessment rather than waiting to see if it settles.

The two kinds of hearing loss

Hearing loss comes in two broad types, and telling them apart drives everything. Conductive loss happens when sound cannot travel through the outer or middle ear — for example, ear wax, fluid behind the eardrum after a cold, or an infection. This is common, usually not urgent, and often reversible. Sensorineural loss comes from the inner ear (the cochlea) or the hearing nerve itself. When it appears suddenly over hours to days in one ear, it is treated as an emergency because the window for effective treatment is short. A quick clue: cover the good ear and hum. If the hum sounds louder in the bad ear it is likely conductive; if quieter, it may be sensorineural.

Why speed matters

Sudden sensorineural hearing loss is defined as a rapid drop in hearing, usually in one ear, over three days or less. The cause is often never found, though it is thought to involve the inner ear's blood supply, a virus, or inflammation. The key message is that a sudden loss of hearing in one ear needs urgent — same-week — ENT assessment, ideally within a few days. Standard NHS treatment is a course of steroid medicine, either as tablets or injected into the ear, to calm inflammation and give the inner ear the best chance to recover. Evidence suggests the sooner treatment starts the better the outcome; waiting weeks can mean permanent loss.

Assessment and investigations

The clinician first looks in the ear to rule out simple causes such as wax or infection, which are easily treated. They perform tuning-fork tests at the bedside to sort conductive from sensorineural loss, then arrange a formal hearing test (audiogram) to measure and confirm the pattern. Because the hearing nerve runs alongside the balance nerve, they also ask about dizziness and check eye movements and facial strength. If a one-sided sensorineural loss is confirmed, an MRI scan is usually arranged afterwards to look at the hearing nerve and rule out a rare growth. Blood tests may be done to look for treatable contributing conditions.

Recovery and safety-netting

Many people regain some or most of their hearing, especially when treatment starts early, but some are left with lasting loss or ongoing tinnitus, and outcomes vary. Follow-up hearing tests track recovery, and an audiologist can help with hearing aids or tinnitus support if needed. The safety-netting message is simple and important: a sudden, unexplained drop in hearing in one ear is not something to "wait out". Contact your GP urgently or seek same-day advice via NHS 111 so you can be seen quickly. If the hearing loss comes with sudden severe dizziness, weakness or drooping of the face, difficulty speaking, or a severe sudden headache, treat it as a possible stroke and call 999.