You wake up and something is off. One ear feels blocked, like the pressure has not equalised after a flight you did not take. You hold the phone to that ear, realise you cannot follow the call, and switch sides without thinking about it. There is a hiss in there too. The obvious explanation arrives on its own: wax. You ring for a syringing appointment, the first one is a week on Thursday, and that seems grand.
That week on Thursday is the problem. A small number of people who go through that exact morning do not have wax. They have sudden sensorineural hearing loss, an inner ear event with a short treatment window, and the window is measured in days rather than months. By the time the appointment comes around, the most useful part of it has usually gone.
TL;DR
- Sudden sensorineural hearing loss means losing at least 30 decibels across three neighbouring pitches in one ear, over three days or less. Those three days define the condition. They are not the treatment deadline.
- The real clock is the guideline’s: a hearing test within 14 days, steroids offered inside two weeks of onset, and injections into the eardrum as a rescue option from two to six weeks.
- Between 32% and 65% of people recover on their own, which is exactly why the evidence on steroids is weaker than most assume. Still worth starting the clock rather than waiting it out.
- There is no page for hearing loss in the HSE Health A to Z. The only HSE instruction to go to an emergency department for sudden hearing loss sits inside the tinnitus page, and only applies if you have tinnitus with it.
- At 24 September 2026, 38,630 adults were waiting for a first ENT outpatient appointment in Ireland, 15,091 of them longer than six months. A routine referral will not beat a 14 day window, so the words you use on the phone matter.
What the condition actually is
Hearing loss comes in two broad flavours. Conductive loss means something is blocking sound on its way in: wax, fluid behind the eardrum, a perforation. Sensorineural loss means the problem is in the cochlea or the hearing nerve itself. From the inside the two can feel almost identical, which is the whole difficulty, and the treatment implications are completely different.
Sudden sensorineural hearing loss is defined with unusual precision for a condition nobody can explain. It is a drop of at least 30 decibels across three adjacent frequencies, developing over three days or less, confirmed on a pure tone audiogram. More than 90% of cases are idiopathic, meaning no cause is ever found, and it is almost always one ear.
The American Academy of Otolaryngology puts the incidence at 5 to 27 cases per 100,000 people a year. Applied to Ireland’s April 2026 population of 5,525,578, that gives roughly 280 to 1,490 new cases a year here. It is an applied estimate; nobody publishes an Irish count. Incidence climbs with age, so a disproportionate share of those cases land among the 1.91 million people in this country aged 50 and over.
It is not common. It is also one of the very few hearing complaints where the speed of your response changes the outcome.
One hint you can use before you get to anybody
You cannot diagnose this at your kitchen table, and nothing here replaces being examined. But there is a rough test doctors have used for well over a century, and it costs nothing while you are deciding how urgently to ring. Hum, steadily, with your mouth closed, and notice which ear the hum seems louder in. If the problem is a blockage like wax, the hum tends to sound louder in the bad ear, which is why your own voice booms inside your head when an ear is plugged. If the loss is sensorineural, the hum usually sounds louder in the good ear. Other features point inward rather than outward: speech sounding distorted or tinny rather than simply quiet, and new tinnitus in that ear alone.
Wax is far more common than any of this, but it does not generally cause a severe one sided drop overnight. Our guide to earwax and ear care after 50 covers what wax genuinely does.
The clock, and what it is actually for
The reference document here is the 2019 update to the American clinical practice guideline on sudden hearing loss, the standard most ENT departments work from. Its recommendations read as a sequence of deadlines. Audiometry should be obtained as soon as possible and within 14 days of onset. Corticosteroids may be offered as initial therapy within two weeks of symptoms starting. Steroid injections through the eardrum are recommended as a rescue option when recovery is incomplete two to six weeks after onset, and hyperbaric oxygen with steroids is an option within two weeks. An MRI or an auditory brainstem response test should rule out a growth on the hearing nerve, with a follow up hearing test at the end of treatment and again within six months.
The guideline is just as firm about what not to do: strongly against a routine CT scan of the head at first presentation, against routine blood tests, and against antivirals, clot busting drugs and vasodilators. That first one matters in an Irish emergency department, where a head CT is the most readily available test at three in the morning and also the one the guideline says not to order here.
The honest part about steroids
It would be easier to write this post if the drug were a certainty. It is not. Between 32% and 65% of people with this condition recover spontaneously, and that recovery tends to happen in the first fortnight. Beyond three months, the prospect of further recovery is minimal. Hold that beside the observational figures usually quoted to justify urgency: of people who reached a doctor and had an audiogram in the first week, roughly 87% recovered; within two weeks, 52%; beyond three months, under 10%. The trouble is that the spontaneous recovery window and the treatment window are the same window, and some researchers argue the apparent benefit of early treatment is partly an artefact of that overlap.
The Cochrane review of steroid injections into the eardrum, covering 30 studies and 2,133 participants, found that as a first treatment they make little or no difference compared with tablets. As a rescue after tablets have failed, the picture is better: far more people saw their hearing improve, though the evidence was rated low certainty, and a 2026 synthesis put that rescue effect at a number needed to treat of about three. The injections carry costs of their own, including persistent eardrum perforation in up to roughly 4% of patients in some series. A large UK trial, STARFISH, is still running across about 75 ENT units to settle which route works best, and has not reported.
The practical reading: this is an option rather than a certainty, the guideline itself tells clinicians to explain the limits of the evidence, and none of that is a reason to spend your fortnight waiting. You cannot be offered a choice you never got in front of anyone to make.
Where Irish advice says this out loud, and where it does not
The HSE’s Health A to Z carries over 500 condition pages. It has pages for earache, ear infections, earwax build up, perforated eardrum, surfer’s ear and newborn hearing screening. It has no page for hearing loss in adults, and no page for sudden hearing loss.
The one place on the HSE website where sudden hearing loss is named as an emergency is inside the tinnitus page. There, under a heading reading “Emergency action required: Call 999 or 112 or go to the nearest emergency department”, the HSE lists tinnitus after a head injury, tinnitus with sudden hearing loss, tinnitus with facial weakness, and tinnitus with a spinning sensation. That advice is correct and strongly worded. It is also conditional on having tinnitus, and it is reached only by someone who went looking for information about ringing in the ears.
Go instead to the page a worried person would most plausibly land on, the HSE’s “If you’re worried about your hearing”, and the entire instruction is to contact your GP. There is no urgency language anywhere on it. It explains, accurately, that HSE audiology handles chronic hearing problems while hospital ENT departments handle acute ones. At the foot of that page sits a line worth noticing: last reviewed 31 January 2023, next review due 31 January 2026. That date has passed.
So the Irish position is not that the health service is wrong about sudden hearing loss. It is that the correct advice exists in precisely one place, behind a different symptom, while the page about being worried about your hearing says only to ring the GP.
The queue the referral letter joins
Say the GP does the right thing and refers you urgently to ENT. Here is the system that letter enters.
National Treatment Purchase Fund figures for 24 September 2026 show 38,630 adults waiting for a first outpatient appointment in otolaryngology. Of those, 23,539 had been waiting under six months, 10,302 between six and twelve months, 3,281 between twelve and eighteen months, and 1,508 longer than eighteen months. Counting adults and children together, ENT is the fourth largest outpatient waiting list in the country.
Set that against a 14 day window and the arithmetic answers itself. An urgent referral does move faster than the routine queue, and this is exactly the sort of thing that should trigger a phone call between a GP and an on call registrar rather than a letter. But only if the problem is described as what it is. “Hearing trouble, please assess” and “sudden one sided sensorineural loss, onset Tuesday, for urgent audiogram and consideration of steroids” are the same patient and two different pathways.
What to do, in order, on the day it happens
- Ring the GP the same day and say the words. Not “my ear is blocked”. Say: sudden hearing loss in one ear, came on over hours or a day, and ask whether it could be sudden sensorineural hearing loss. Ask about steroids and an urgent ENT referral. You are not being difficult; you are supplying the trigger phrase.
- Treat neurological symptoms as an emergency. If sudden hearing loss arrives with vertigo, double vision or vision loss, slurred speech, facial weakness, or weakness or numbness in an arm or leg, that is 112 or 999, not a GP appointment. Sudden hearing loss can be the opening symptom of a stroke in the back of the brain.
- Out of hours, use the out of hours service rather than waiting for Monday. The GP co operatives cover nights and weekends, and HSE Live on 1800 700 700 can point you to yours. A Friday evening onset should not sit untouched until Monday afternoon.
- If you cannot get an audiogram quickly, get one anyway. High street providers offer free adult hearing tests with no referral: Hidden Hearing runs more than 85 clinics nationwide, performs pure tone audiometry and gives results the same day, and Specsavers tests adults free. This is not treatment and not a substitute for seeing your GP, which you should do regardless. What it gives you is the measurement, printed and dated, inside the 14 days.
- Keep every audiogram. Follow up testing is part of the guideline, and comparing the shape of the curve over time is how recovery gets judged.
Two Irish gaps worth knowing about
The guideline offers hyperbaric oxygen, combined with steroids, as an option within two weeks and as salvage within a month. Ireland has one National Hyperbaric Medicine Unit, at University Hospital Galway. The indications it lists publicly are gas emboli, carbon monoxide poisoning, necrotising fasciitis and decompression illness. Sudden hearing loss is not among them. The one Irish facility that does list “acute sensorineural hearing loss (sudden deafness)” is a private centre in Santry in Dublin, which takes GP or consultant referral and prices sessions from €150, with courses running from 10 to 40 sessions and the note that the HSE pays in some cases. A ten session course therefore starts around €1,500, for something the guideline rates as an option rather than a recommendation.
The second gap is quieter and matters more. A growth on the hearing nerve, a vestibular schwannoma, is found in between 1.4% and 6.1% of people presenting with sudden sensorineural hearing loss, and 10% to 20% of these growths announce themselves with a sudden drop in hearing. The critical line in the literature: recovery of the hearing, spontaneous or treated, does not rule out an underlying mass. If your hearing comes back and the scan gets quietly dropped from the plan, that is the moment to ask for it to be put back.
If the hearing does not fully return
Age is the most consistent adverse factor in recovery, which is an uncomfortable sentence to write on a site for people over 50 and a dishonest one to leave out. Severe loss at the outset, vertigo alongside it, and diabetes, high cholesterol or high blood pressure also carry poorer outcomes. None of that is destiny, and it is an argument for moving faster, not for skipping treatment.
Where hearing in one ear does not come back, the task shifts from rescue to rehabilitation, and that is a well served area. The Treatment Benefit Scheme pays up to €500 towards each hearing aid once every four calendar years for those with the PRSI record, plus one repair per aid up to €100, and medical card holders get aids free through HSE audiology. For some people with one deaf ear the options run further than a conventional aid, and our piece on cochlear implants after 60 covers how Ireland’s national programme at Beaumont assesses suitability. Between 4% and 8% of people go on to develop Ménière’s disease in later years, so new vertigo and fluctuating hearing deserve a mention to your GP rather than a shrug.
And do not let a one sided loss settle quietly into the background. Untreated hearing loss is one of the largest modifiable risk factors for dementia, as we set out in our guide to hearing loss and brain health. The ear you still have is doing more work than you think.
The one sentence worth keeping
If hearing disappears from one ear over a day or less, treat it the way you would treat sudden vision loss in one eye: as something to be looked at today, not next Thursday. You may well turn out to have wax, and that would be a good outcome, cheaply bought. The version where you wait is the version where the fortnight runs out while you are still assuming.
At Críonna Health we write about ageing as something to be equipped for rather than endured, and most of what we cover rewards patience. This is one of the few things that does not. For the longer view, our guide to hearing health after 50 is the place to start.
This article is for general information and is not a substitute for individual medical advice. If you experience sudden hearing loss, contact your GP the same day, or call 112 or 999 if it comes with neurological symptoms.
