What causes tinnitus (ringing in the ears)?

Causes of Tinnitus (Ringing in the Ears)

Tinnitus is most commonly caused by sensorineural hearing loss, but can also result from various other conditions including vascular abnormalities, neurologic disorders, and certain medications. 1, 2

Primary Causes of Tinnitus

Hearing-Related Causes (Most Common)

• Sensorineural hearing loss - The most frequent underlying cause 1
  • Noise exposure (occupational or recreational)
  • Age-related hearing loss (presbycusis)
  • Ototoxic medications (certain antibiotics, NSAIDs, chemotherapy drugs)

Other Common Causes

• Ear pathology

  • Cerumen impaction (earwax blockage)
  • Middle ear effusion
  • External ear infection
  • Otosclerosis
  • Menière's disease 3, 4

• Neurologic causes

  • Vestibular schwannoma (acoustic neuroma) - especially with unilateral tinnitus
  • Traumatic brain injury
  • Migraine 5

• Vascular causes (often present as pulsatile tinnitus)

  • Dural arteriovenous fistulas
  • Arteriovenous malformations
  • Carotid or vertebral artery abnormalities
  • Sigmoid sinus wall abnormalities 2

Types of Tinnitus

Subjective Tinnitus (Most Common)

• Only the patient can hear the sound
• Represents phantom sensation where abnormal neural activity is generated in the ear, auditory nerve, or central nervous system 6

Objective Tinnitus (Rare)

• Sound can be heard by an examiner
• Usually caused by vascular abnormalities of the carotid artery or jugular venous systems 4

Classification by Pattern

• Pulsatile tinnitus - Synchronous with heartbeat, suggests vascular cause
• Non-pulsatile tinnitus - Continuous sound, typically associated with hearing disorders

Risk Factors and Associated Conditions

• Environmental factors

  • Noise exposure
  • Military service

• Medical conditions

  • Hearing loss
  • Small vessel disease
  • Insomnia
  • Anxiety and depression 5

• Lifestyle factors

  • Smoking
  • Stress
  • Socioeconomic status 5

Diagnostic Approach

When evaluating tinnitus, clinicians should consider:

1. Unilateral vs. bilateral presentation

   • Unilateral tinnitus warrants more urgent evaluation (possible vestibular schwannoma) 2, 3

2. Pulsatile vs. non-pulsatile

   • Pulsatile tinnitus requires vascular imaging 2

3. Associated symptoms

   • Hearing loss
   • Vertigo
   • Focal neurological abnormalities 2

Important Clinical Considerations

• Tinnitus often represents more than simple ringing in the ears and may be accompanied by many distressing changes affecting quality of life 7

• The anatomical location of chronic subjective tinnitus is rarely in the ear but more often in the auditory nervous system 6

• Patients with severe tinnitus may experience sound distortion, hyperacusis (reduced tolerance to sounds), or phonophobia (fear of sounds) 6

• Cognitive behavioral therapy is the most effective evidence-based treatment for persistent tinnitus 2

• Patients with tinnitus accompanied by severe anxiety or depression require prompt identification and intervention, as suicide has been reported in patients with tinnitus who have coexisting psychiatric illness 1

Understanding the specific cause of tinnitus is essential for appropriate management and improving quality of life for affected individuals.