Tinnitus

Tinnitus refers to a persistent addition sound that is heard but is not present in the surrounding environment. It may be described as a “ringing in the ears”, but it can also be a buzzing, hissing or humming noise. 

The additional noise experienced with tinnitus is thought to be the result of a background sensory signal produced by the cochlea that is not effectively filtered out by the central auditory system. In a quiet enough environment, almost everyone will experience some background noise (tinnitus). This becomes more prominent the more attention it is given.

 

Causes

Primary tinnitus has no identifiable cause and often occurs with sensorineural hearing loss. 

Secondary tinnitus refers to tinnitus with an identifiable cause. Causes include:

  • Impacted ear wax
  • Ear infection
  • Ménière’s disease
  • Noise exposure
  • Medications (e.g., loop diuretics, gentamicin and chemotherapy drugs such as cisplatin)
  • Acoustic neuroma
  • Multiple sclerosis
  • Trauma
  • Depression

 

Tinnitus may also be associated with systemic conditions:

  • Anaemia
  • Diabetes
  • Hypothyroidism or hyperthyroidism
  • Hyperlipidaemia

 

Objective tinnitus refers to when the patient can objectively hear an extra sound within their head. This sound can also be observable on examination by auscultating with a stethoscope around the ear. Actual additional sounds may be caused by:

  • Carotid artery stenosis (pulsatile carotid bruit)
  • Aortic stenosis (radiating pulsatile murmur sounds)
  • Arteriovenous malformations (pulsatile)
  • Eustachian tube dysfunction (popping or clicking noises)

 

TOM TIP: I think of primary tinnitus as the ears trying to “turn up the volume” when they cannot hear the surrounding noises as well. This is a helpful way of explaining it to patients who have tinnitus associated with hearing loss. Using hearing aids allows the ears to pick up noises better and “turn the volume down”, improving the tinnitus. The actual cause of tinnitus is not entirely understood, so this is not entirely accurate, but it is a helpful analogy.

 

Assessment

Ask about the pattern of symptoms:

  • Unilateral or bilateral
  • Frequency and duration
  • Severity
  • Pulsatile or non-pulsatile (pulsatile may indicate a cardiovascular cause, such as carotid artery stenosis with a bruit)

 

A focused history and examination can be used to identify any underlying causes, including:

  • Contributing factors, such as hearing loss or noise exposure
  • Associated symptoms (e.g., hearing loss, vertigo, pain or discharge)
  • Stress and anxiety
  • Otoscopy to look for causes such as ear wax or infection
  • Weber’s and Rinne’s tests for hearing loss

 

Investigations

The NICE clinical knowledge summaries (updated March 2020) suggest considering blood tests for possible underlying causes:

  • Full blood count (anaemia)
  • Glucose (diabetes)
  • TSH (thyroid disorders)
  • Lipids (hyperlipidaemia)

 

Audiology can be used to assess the hearing in detail and help establish the underlying cause.

Imaging (e.g., CT or MRI) may be rarely required to investigate for underlying causes such as vascular malformations or acoustic neuromas.

 

Red Flags

Red flags that could indicate a serious underlying cause and the need for specialist assessment include:

  • Unilateral tinnitus
  • Pulsatile tinnitus
  • Hyperacusis (hypersensitivity, pain or distress with environmental sounds)
  • Associated unilateral hearing loss
  • Associated sudden onset hearing loss
  • Associated vertigo or dizziness
  • Headaches or visual symptoms
  • Associated neurological symptoms or signs (e.g., facial nerve palsy or signs of stroke)
  • Suicidal ideation related to the tinnitus

 

Management

Tinnitus tends to improve or resolve over time without any interventions. 

Underlying causes of tinnitus can be treated, such as impacted ear wax or infection.

Several measures can be used to help improve and manage symptoms:

  • Hearing aids
  • Sound therapy (adding background noise to mask the tinnitus)
  • Cognitive behavioural therapy

 

Last updated July 2021
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