PATIENT INFORMATION

Sudden Hearing Loss

Sudden hearing loss is a marked reduction in hearing that develops within hours or over a few days; it usually affects one ear and can be mistaken for a feeling of blockage or fullness in the ear. A sudden hearing loss that cannot be explained by a cause in the ear canal or middle ear may originate in the inner ear, and clinical guidelines treat it as a condition that must be assessed without delay. This page explains what sudden hearing loss means, how it differs from a blocked ear, why timely assessment matters, what is done in the ENT examination and the general principles of treatment.

Medical illustration of the ear canal, inner ear and hearing nerve with incoming sound waves

Sudden hearing loss must be assessed without delay

A reduction in hearing in one or both ears that develops over up to three days and cannot be explained by a cause in the ear canal or middle ear is treated in clinical guidelines as a condition requiring assessment without delay. The NICE guideline published in the United Kingdom (NG98) recommends immediate referral so that the patient is seen by a specialist within 24 hours when such a hearing loss has occurred within the last 30 days; that interval is a referral criterion defined for that country’s health service and is not a commitment about service times in Türkiye. The practical message for the patient is this: assessment of an unexplained sudden reduction in hearing should not be postponed.

If the following symptoms accompany the hearing loss, the picture may also suggest an urgent cause in the nervous system, and assessment should take place as emergency medical care:

Drooping, weakness or altered sensation on one side of the face
Other nervous-system symptoms such as slurred speech, double vision, difficulty swallowing, or weakness or numbness of an arm or leg
Sudden dizziness accompanied by new, severe unsteadiness or difficulty walking

The following features do not change the level of urgency, because an unexplained sudden hearing loss in one or both ears already requires assessment without delay. They matter for the search for a cause, however, and must be mentioned at the examination:

Hearing loss that has occurred in both ears at the same time
Previous episodes of similar hearing loss

These symptoms are not present in everyone with sudden hearing loss and do not on their own indicate a particular diagnosis; when they are present, however, assessment must not be postponed and, where necessary, the emergency department should be attended. Even without these symptoms, an unexplained sudden hearing loss itself requires medical assessment without delay.

What is sudden hearing loss?

Sudden hearing loss is a marked reduction in hearing that develops over a short period, usually within hours or over up to three days. It most often affects one ear; people frequently notice it on waking in the morning or when holding the telephone to that ear.

The hearing loss may be accompanied by a feeling of fullness or pressure in the ear, tinnitus and sometimes dizziness. Ear pain or discharge may suggest a different or additional cause in the outer or middle ear and is assessed separately at the examination.

Clinical guidelines define sudden sensorineural hearing loss (SSNHL) as a loss arising in the inner ear or hearing nerve that develops within three days (72 hours) and is measured at a defined level across three consecutive frequencies on a hearing test. Whether these criteria are met can only be determined with a hearing test; the distinction cannot be made from the severity of the complaint.

In a considerable proportion of cases no definite cause is found despite detailed investigation; this is termed idiopathic. That no cause has been found does not mean the assessment was unnecessary: one of its purposes is to identify causes that are treatable or require a different approach.

Is it the same as a blocked ear?

A reduction in hearing can arise through two different mechanisms, and both often feel the same to the person, as though the ear were blocked:

Conductive loss: Causes in the ear canal or middle ear that prevent sound from reaching the inner ear; for example an earwax plug, inflammation of the ear canal, fluid in the middle ear after an upper respiratory infection, or eardrum problems.
Sensorineural loss: Causes in the inner ear or hearing nerve. This is primarily the picture that makes sudden hearing loss a condition requiring assessment without delay.

It is not possible to tell at home which mechanism is involved; the distinction is made by examination and a hearing test. It is therefore not appropriate to wait on the assumption that “it is probably earwax”, or to lose time with ear drops or attempts at ear cleaning.

The fact that hearing has not disappeared completely does not make the situation unimportant: sudden hearing loss usually takes the form of a partial reduction rather than total deafness.

Why does timely assessment matter?

Some of the causes of sudden hearing loss are conditions that need to be recognised and treated early. Guidelines state that a hearing test to confirm the diagnosis should be performed as soon as possible, within two weeks of the onset of symptoms, and that corticosteroid treatment is an option that can be considered within the first two weeks. These are the assessment and treatment windows defined by the guidelines.

In a proportion of patients hearing recovers spontaneously. Which individuals fall into this group cannot be known at the outset, however, and waiting for spontaneous recovery is no substitute for assessment. Among the factors associated with the prospect of recovery, the guidelines include the time between the onset of symptoms and treatment. This does not mean that early assessment guarantees recovery; it means that staying within the time windows defined by the guidelines matters.

The second purpose of timely assessment is to ensure that causes underlying the hearing loss which require a different approach are not missed.

What is done in the ENT assessment?

The assessment begins with a detailed history: how quickly the hearing loss developed, whether it affects one or both ears, accompanying tinnitus, dizziness, fullness, pain or discharge, recent infection, injury or pressure change, medicines being taken and previous ear disease.

During the examination the ear canal and eardrum are inspected with an otoscope; conductive causes such as an earwax plug, inflammation, a perforated eardrum or fluid in the middle ear may be seen at this stage. Tuning-fork tests are a simple examination step that helps to distinguish conductive from sensorineural loss before the hearing test.

Where the symptoms call for it, examination of the facial nerve, eye movements and balance also forms part of the assessment.

Hearing test and further investigations

A hearing test (audiometry) is the basic investigation for this condition: it shows whether a loss is really present, its degree, and whether it is conductive or sensorineural. The diagnosis is made with this test together with the examination findings.

When a sensorineural loss is found, MRI or an auditory brainstem response (ABR) test may be considered to investigate causes involving the hearing nerve and the inner-ear pathway. Guidelines do not recommend routine CT scanning of the brain or routine blood tests in the initial assessment; which investigations are needed is decided individually according to the findings.

Repeating the hearing test during and after treatment is important for monitoring recovery.

How is the treatment approach decided?

Treatment is planned according to the mechanism identified. When a conductive cause is found (for example an earwax plug or fluid in the middle ear), treatment is directed at that cause.

In idiopathic sudden sensorineural hearing loss, corticosteroid treatment appears in current guidelines as an option that can be considered within the first two weeks. Whether it is given, in what form and for how long is decided individually by the physician. In cases without adequate recovery, steroid treatment applied through the eardrum (intratympanic) within a defined period may be considered as an option administered by the physician.

Guidelines do not recommend the routine use of antiviral medicines, vasodilators or medicines intended to increase blood flow in sudden sensorineural hearing loss.

No treatment guarantees that hearing will be regained; among the factors the guidelines associate with the prospect of recovery are age, dizziness at onset, the degree of loss, the shape of the audiogram and the time between the onset of symptoms and treatment. When hearing loss or tinnitus persists, hearing-aid and auditory rehabilitation options are assessed separately.

This page deliberately contains no drug names, doses or treatment durations; medication must not be started without a physician’s assessment.

Frequently asked questions

My ear feels blocked; can I wait a few days?

A simple cause such as earwax cannot be distinguished at home from a loss originating in the inner ear, and the two can feel the same. In an unexplained sudden reduction in hearing, assessment by examination and a hearing test is recommended rather than waiting.

Can sudden hearing loss recover on its own?

Spontaneous recovery is seen in a proportion of patients. It cannot be known in advance who will recover, however, and waiting is no substitute for assessment. Guidelines define early time windows for confirming the diagnosis and for considering some treatment options.

Does it matter that only one ear is affected?

Sudden hearing loss usually affects one ear; one-sided loss is the expected picture and does not change the need for assessment. Loss in both ears at the same time is less common and requires a broader assessment.

What does it mean if I also have dizziness?

In inner-ear conditions, dizziness may accompany hearing loss; dizziness at onset is also among the factors that influence the prospect of recovery. If severe loss of balance or nervous-system symptoms are present, assessment must not be delayed, as set out in the warning section above.