What sudden hearing loss is
Sudden sensorineural hearing loss is a loss of inner-ear hearing that develops over hours, or at most three days. It usually affects one ear. Many people notice it on waking. A blocked or full feeling is the commonest first symptom, and tinnitus is frequent; some people also have dizziness or spinning vertigo.
The definition used by the American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS) is a drop of at least 30 dB at three consecutive test frequencies, developing within 72 hours. Because an earlier audiogram is rarely available, the affected ear is compared with the other one. Smaller drops are still taken seriously in practice.
It is uncommon: between 5 and 27 people per 100,000 each year. It is not the same as the gradual sensorineural hearing loss of age or noise.
Why the first days matter
Sudden sensorineural hearing loss should be assessed the same day. Treatment is offered in the first days and weeks, and the chance of recovery depends partly on how soon it starts. Because a blocked-feeling ear is common and usually harmless, patients and doctors are tempted to wait; that is the delay to avoid.
Same-day assessment means an ear examination, a hearing test as soon as possible (within 14 days at the latest, in the American guideline) and a decision about treatment, which should not wait if a hearing test cannot be done at once.
If the hearing loss comes with facial weakness, slurred speech, double vision, weakness or numbness in an arm or leg, or a severe headache, call emergency services: rarely, a sudden hearing loss is part of a stroke. A loss in both ears at once, or repeated episodes, also points away from the usual pattern and needs a wider search for a cause.
After ear surgery the same rule applies to the operated ear: a sudden drop in hearing, or severe or spinning vertigo, needs review the same day. See when to contact your surgeon and what is normal after stapedotomy.
Blocked ear or inner ear?
The first task is to tell a conductive loss (wax, fluid behind the eardrum, a perforation) from a sensorineural one. A doctor looks in the ear and uses tuning fork tests; the audiogram with bone conduction and tympanometry settle it (see interpreting hearing tests).
A simple check some surgeons suggest: hum with your mouth closed. When an ear is blocked by wax or fluid, the hum normally sounds louder in that ear. If it sounds louder in the other, better ear, the inner ear may be affected. This is a rough guide only, and less reliable if the other ear also hears poorly. It does not replace an examination and a hearing test, and a reassuring hum is never a reason to wait.
Causes
In about nine cases out of ten no cause is found, even after full investigation (idiopathic sudden sensorineural hearing loss). A viral, inflammatory or circulatory problem in the cochlea is often suspected but unproven, and the cause may differ from person to person.
Identifiable causes are uncommon but matter. They include a vestibular schwannoma (a benign tumour on the hearing and balance nerve), stroke, Ménière’s disease, autoimmune inner-ear disease, head injury or pressure trauma, inner-ear damage from some medicines, and complications of ear surgery.
For this reason, everyone with an unexplained sudden sensorineural loss should have an MRI scan of the inner ears and hearing nerves, or, if MRI is not possible, another scan or a test of the nerve’s electrical response. In a recent systematic review a vestibular schwannoma was found in fewer than 4 in 100. The scan does not delay treatment, and it is still worth doing if hearing recovers.
Work-up in the 2019 AAO-HNS guideline
Definition: subjective hearing loss developing over 72 hours; sensorineural, conventionally ≥30 dB at three consecutive frequencies relative to the contralateral ear; idiopathic in over 90%. Recommended: distinguish conductive from sensorineural loss at presentation (strong recommendation); audiometry within 14 days; look for bilateral loss, recurrent episodes and focal neurological signs. Strongly recommended against: routine head CT and routine laboratory tests. Retrocochlear work-up by MRI, CT if MRI is impossible, ABR secondarily; audiometric follow-up alone is no longer adequate. MRI yield for vestibular schwannoma in sudden SNHL was 3.66% in the updated Congress of Neurological Surgeons systematic review.
Treatment
No treatment has been proven beyond doubt, and that uncertainty belongs in the discussion.
Steroid tablets are the most widely used first treatment, as a short course. A Cochrane review found only three placebo-controlled trials, all small and at high risk of bias, with contradictory results, and judged their value unclear. The 2019 AAO-HNS guideline lists them as an option, started within two weeks of onset. Raised blood sugar is the side effect that matters most, particularly in diabetes.
Intratympanic steroids are injected through the numbed eardrum into the middle ear, reaching the inner ear in high concentration with little effect on the rest of the body, usually as several injections over one to two weeks. They are used in two ways:
- As first treatment, instead of or alongside tablets. A 2022 Cochrane review of 30 trials found little or no difference from tablets, and possibly a small extra benefit from combining both (low certainty). Injections are useful when tablets are unsuitable.
- As salvage treatment, when hearing has not recovered after first treatment. The guideline recommends offering this between two and six weeks after onset. In the same review, salvage injections made some improvement much more likely than no treatment, although the average gain in hearing level was modest.
Ear pain, brief dizziness at the time of injection and, uncommonly, a lasting small perforation of the eardrum (in up to about 1 in 20 patients in most trials) are the main drawbacks.
Hyperbaric oxygen means breathing pure oxygen in a pressurised chamber, in a course of sessions. A Cochrane review of seven small trials found some improvement in recent sudden loss, of unclear clinical importance, and none when the loss was months old. The 2019 guideline lists it as an option with steroids, within two weeks of onset or as salvage within a month. Availability is limited, it takes time, and it carries risks, including pressure injury to the ear.
Antiviral drugs, vasodilators and clot-dissolving drugs are not recommended for routine use.
The evidence in numbers
Systemic steroids (Cochrane 2013): three RCTs, 267 participants, all at high risk of bias; one showed improvement in 61% with steroid against 32% in controls, two showed no effect; no meta-analysis possible. Intratympanic steroids (Cochrane 2022, 30 RCTs, 2133 participants): as primary therapy versus systemic, RR for improvement 1.04 (moderate certainty) and mean difference about 6 dB (low certainty); combined versus systemic alone, about 8.5 dB (low certainty); as secondary therapy versus no treatment or placebo, RR for improvement 5.55 but mean threshold gain about 9 dB (both low certainty); persistent perforation 0–5.5% in most comparisons and 8.1% in one small trial of combined salvage therapy. Hyperbaric oxygen (Cochrane 2012, 7 trials, 392 participants): RR 1.39 for a 25% improvement in pure-tone average, NNT 5, mean gain 15.6 dB, with poor reporting and wide confidence intervals; no effect in chronic presentation.
Will the hearing come back?
Often partly, sometimes completely, sometimes not at all. The guideline puts spontaneous recovery at no more than 32–65%, possibly less. In pooled data on untreated or placebo-treated patients, 70% gained at least 10 dB and 36% at least 30 dB by three months. In a classic prospective study, most of those who recovered did so within 14 days.
Recovery is less likely when the loss is severe or total, when there was vertigo at onset, in older people, and when treatment starts late. Losses mainly in the low pitches tend to do better than losses in the high pitches.
A follow-up hearing test at the end of treatment, and again within six months, shows where hearing has settled. Further change after the first months is uncommon.
If hearing does not return
A permanent loss in one ear is more disabling than the audiogram suggests. Finding where sound comes from, following conversation in noise and the effort of listening are all affected, because these depend on two ears working together. Tinnitus in the affected ear is common, and anxiety in the first weeks is understandable.
Where some residual hearing remains, a hearing aid may suffice. Where the ear is deaf, the options are a CROS aid (routing sound from the deaf side to the hearing ear), a bone-conduction device, or a cochlear implant, the only one that restores some hearing in the deaf ear itself. See single-sided deafness and hearing rehabilitation. Protecting the remaining ear from noise matters more than ever.
Sources
- Chandrasekhar SS, Tsai Do BS, Schwartz SR, et al. Clinical Practice Guideline: Sudden Hearing Loss (Update). Otolaryngol Head Neck Surg. 2019;161(1_suppl):S1-S45. PubMed
- Stachler RJ, Chandrasekhar SS, Archer SM, et al. Clinical practice guideline: sudden hearing loss. Otolaryngol Head Neck Surg. 2012;146(3 Suppl):S1-35. PubMed
- Wei BP, Stathopoulos D, O’Leary S. Steroids for idiopathic sudden sensorineural hearing loss. Cochrane Database Syst Rev. 2013;2013(7):CD003998. PubMed
- Plontke SK, Meisner C, Agrawal S, et al. Intratympanic corticosteroids for sudden sensorineural hearing loss. Cochrane Database Syst Rev. 2022;7(7):CD008080. PubMed
- Bennett MH, Kertesz T, Perleth M, Yeung P, Lehm JP. Hyperbaric oxygen for idiopathic sudden sensorineural hearing loss and tinnitus. Cochrane Database Syst Rev. 2012;10(10):CD004739. PubMed
- Ying YM, Tseng CC, Shin J, Rauch S. Natural History of Untreated Idiopathic Sudden Sensorineural Hearing Loss. Laryngoscope. 2024;134(Suppl 9):S1-S15. PubMed
- Mattox DE, Simmons FB. Natural history of sudden sensorineural hearing loss. Ann Otol Rhinol Laryngol. 1977;86(4 Pt 1):463-80. PubMed
- Strickland BA, Honaker JA, Olson JJ. Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines Update for the Role of Audiologic Screening in the Diagnosis and Management of Patients With Vestibular Schwannomas. Neurosurgery. 2026;98(2):278-282. PubMed
Common questions
What should I do if I wake up deaf in one ear?
Get it assessed the same day, by your doctor, an ear, nose and throat (ENT) service or an emergency department. Ask whether it could be a sudden inner-ear hearing loss and whether a hearing test can be done. Do not wait a few days to see whether it clears, and do not assume it is wax. If you also have facial weakness, slurred speech, double vision, weakness in an arm or leg, or a severe headache, call emergency services.
Do steroids work for sudden hearing loss?
Possibly, but the evidence is weaker than many people expect. The few placebo-controlled trials of steroid tablets are small and disagree, and a Cochrane review called their value unclear. Because some benefit is possible, the course is short and side effects are usually manageable, guidelines regard steroids as a reasonable option within two weeks of onset. People with diabetes, stomach ulcers or some other conditions need special care.
What is an intratympanic steroid injection?
A steroid is injected through the eardrum into the middle ear after the eardrum has been numbed, so that it can reach the inner ear in a high concentration with little effect on the rest of the body. Several injections are usually given over one to two weeks. It can be the first treatment, or a second treatment when hearing has not recovered. Pain, brief dizziness and, uncommonly, a lasting small hole in the eardrum can occur.
Does hyperbaric oxygen help sudden hearing loss?
It may help some people. Hyperbaric oxygen means breathing pure oxygen in a pressurised chamber, usually in a series of daily sessions. Small trials suggest a modest improvement in hearing when it is given within the first weeks, combined with steroids, but the size of the benefit and who gains most are uncertain. It is not available everywhere and has its own risks, including pressure injury to the ear.
Can sudden hearing loss get better on its own?
Yes, often partly and sometimes completely. Estimates of spontaneous recovery range from about a third to, at most, two-thirds of patients, and most of it happens in the first two weeks. Recovery is less likely when the loss is severe, when there was spinning vertigo at onset, and in older people. Because nobody can predict it for an individual, early assessment still matters.
Why do I need an MRI scan after sudden hearing loss?
To look for a vestibular schwannoma, a benign tumour on the hearing and balance nerve, and for other rare causes. Such a tumour is found in only a few per cent of people with sudden sensorineural loss, but sudden loss can be its first sign, and it changes the follow-up. The scan is usually done in the weeks after onset and does not delay treatment.
This page provides general educational information. It cannot replace an individual assessment, which depends on a full history, examination, audiometry and, where relevant, imaging. If you have sudden hearing loss, severe pain, facial weakness, severe dizziness or discharge with fever, seek medical care promptly.