Sudden hearing loss in one ear: what to do today

If the hearing in one ear has dropped, muffled or disappeared over the last few hours or days, treat it as urgent. Do not wait a week to see whether it clears. The NHS advises asking for an urgent GP appointment or getting help from NHS 111 if you have sudden hearing loss in one or both ears. It might not be anything serious, but it may need to be treated quickly.

Is sudden hearing loss an emergency?

Yes, when there is no obvious cause in the outer or middle ear. The NICE quality standard for hearing loss in adults describes sudden hearing loss in one or both ears that is not explained by external or middle ear causes as an emergency. It sets two timeframes:

• hearing loss that developed over 3 days or less, within the past 30 days, needs immediate referral so a specialist sees you within 24 hours, in an ENT service or an emergency department
• sudden hearing loss that began more than 30 days ago needs urgent referral, to be seen within 2 weeks

The reason is that the treatment window is short. In a UK study reported by ENT UK, which followed 812 adults across 76 hospitals in England and Wales, people who received steroids within seven days of onset were five times more likely to fully recover their hearing than people who were not treated. Only around 60% were treated within that window.

What causes sudden hearing loss?

Many causes are ordinary and treatable. A cold affecting the middle ear, an outer ear infection such as swimmer's ear, or a perforated eardrum after an infection, a very loud noise or a change in air pressure when flying can all make hearing drop suddenly. These are often conductive problems, where sound cannot travel properly through the ear canal or middle ear.

Sudden sensorineural hearing loss is different. The problem sits in the inner ear or the hearing nerve. ENT UK's pathway defines it as a loss of at least 30 dB across three consecutive frequencies, developing over 72 hours or less. The first step recommended by the American Academy of Otolaryngology guideline is to tell sensorineural loss apart from conductive loss.

Sometimes a specific cause is found. NICE lists treatable causes that need prompt investigation, including autoimmune disease, chronic infection, a rapidly growing vestibular schwannoma (a benign growth on the hearing and balance nerve) and stroke. Inner ear conditions such as labyrinthitis or Ménière's disease can also affect hearing, often with dizziness, a spinning sensation or tinnitus. Often, though, no single cause is identified, and the condition is called idiopathic sudden sensorineural hearing loss.

Does it matter if both ears are affected?

Sudden sensorineural hearing loss usually affects one ear, but loss in both ears follows the same urgent route, and NICE's standard covers one or both. Mention any other new symptoms, such as weakness, a drooping face, slurred speech, confusion or a severe headache. Call 999 straight away if any of those appear.

What happens at the urgent assessment?

Expect questions about how quickly your hearing changed, dizziness, tinnitus, pain or discharge, recent illness or injury, medicines and your general health, including any autoimmune conditions. Your ears will be examined and your hearing tested, sometimes with a tuning fork first, followed by a formal hearing test called pure-tone audiometry. ENT UK's pathway also includes an MRI scan to look for rarer causes.

If the picture fits idiopathic sudden sensorineural hearing loss, NICE says it is typically treated with oral steroids as soon as possible. The ENT UK pathway for adults with suspected one-sided loss uses a short course of oral steroids and a repeat hearing test within 10 to 14 days. If hearing has not improved, it suggests considering steroid injections through the eardrum, known as intratympanic steroids. Steroids carry risks for some people, so the team will weigh them against your health history.

Some hearing recovers without treatment. The Undersea and Hyperbaric Medical Society cites an estimate that as many as 65% of cases may resolve on their own. Nobody can tell in advance whose will, which is why the NHS pathway moves quickly.

Where does hyperbaric oxygen therapy fit?

Hyperbaric oxygen therapy (HBOT) means breathing concentrated oxygen inside a pressurised chamber. The inner ear has a high oxygen demand and a sparse direct blood supply, which is the reasoning behind trying it in sudden sensorineural hearing loss.

It has a place in some specialist guidance, always as an addition to standard care:

• The American Academy of Otolaryngology 2019 guideline says clinicians may offer HBOT combined with steroids within 2 weeks of onset, or as salvage treatment within 1 month. Both are graded as options rather than recommendations.
• The Undersea and Hyperbaric Medical Society added idiopathic sudden sensorineural hearing loss to its list of indications in 2011. It suggests considering HBOT for moderate to profound loss, 41 dB or more, within 14 days of onset. Its recommended profile is 100% oxygen at 2.0 to 2.5 ATA for 90 minutes daily, over 10 to 20 treatments, alongside oral steroids and continued ENT follow-up.
• ENT UK's 2020 pathway for suspected one-sided idiopathic sudden sensorineural hearing loss does not include HBOT. Its escalation step is intratympanic steroids.

In England, the NHS routinely commissions hyperbaric oxygen for only two conditions, decompression illness and gas embolism. Whether HBOT has any role in your care is a decision for your ENT specialist.

What does the research show?

The evidence is encouraging in places and limited overall.

A Cochrane review pooled seven trials with 392 participants. For acute sudden hearing loss, HBOT improved hearing, but the reviewers said the clinical significance remains unclear, and they described the trials as small and generally of poor quality. They found no evidence of benefit for long-standing hearing loss or tinnitus, and did not recommend HBOT for those.

A 2022 meta-analysis in JAMA Otolaryngology included three randomised trials, with 88 people receiving HBOT and 62 receiving medical treatment alone. HBOT as part of combination treatment was associated with better hearing, an average of about 10 dB more hearing gain. Three trials and 150 people is a small base, and a published letter in the same journal questioned how the analysis was carried out.

None of this is a promise for any individual. It describes averages in selected patients, treated early, alongside steroids, under specialist protocols.

Can a private HBOT clinic treat sudden hearing loss?

Not as a replacement for urgent care, and not in the way the research describes. Our chamber at HBOT Medics runs at 1.5 ATA. That is below the 2.0 to 2.5 ATA used in the specialist protocol, so the results above cannot be assumed to apply to a session with us.

If you have sudden hearing loss now:

1. Contact your GP urgently or NHS 111 today.
2. Follow the ENT team's plan, including steroids if they advise them.
3. Do not delay that care to book any hyperbaric session, including ours.

Pressure changes also affect the ears. Ear and sinus problems are one of the areas our medical screening looks at before anyone is pressurised, so anyone with a recent ear problem should be cleared by their ENT team before considering HBOT at all. To understand the mechanism, read what HBOT is and how hyperbaric oxygen therapy works.

The short version

Sudden hearing loss is time critical. Same-day help, a proper hearing test and early steroids where appropriate come first. HBOT is a specialist add-on with supportive but limited evidence at higher pressures, and the conversation about it belongs with your ENT specialist.