What are the causes of tinnitus (ringing in the ear)?

Common Causes of Tinnitus (Ringing in the Ear)

Tinnitus is most commonly caused by sensorineural hearing loss, with other significant causes including cerumen impaction, middle ear disorders, vascular abnormalities, neurologic conditions, and medication side effects. 1, 2

Primary Causes of Tinnitus

Hearing-Related Causes

• Sensorineural hearing loss - Most common cause 2
  • Noise exposure (occupational or recreational)
  • Age-related hearing loss (presbycusis)
  • Ototoxic medications (aminoglycosides, loop diuretics, chemotherapy)

Ear-Related Causes

• Cerumen impaction - Easily treatable cause 3
• Middle ear disorders
  • Otitis media
  • Middle ear effusion
  • Otosclerosis
  • Eustachian tube dysfunction
• Ménière's disease - Associated with fluctuating hearing loss and vertigo 4
  • Characterized by episodes of vertigo lasting 20 minutes to 24 hours
  • Accompanied by fluctuating hearing loss and ear fullness

Vascular Causes (Often Pulsatile Tinnitus)

• Carotid artery atherosclerosis
• Arteriovenous malformations (AVMs)
• Arteriovenous fistulae (AVFs)
• Glomus tumors
• Vascular abnormalities of jugular venous systems 3

Neurologic Causes

• Acoustic neuroma (vestibular schwannoma) - Particularly with unilateral tinnitus 2
• Intracranial hypertension
• Head or neck trauma 5

Other Causes

• Medication side effects
  • Aspirin and NSAIDs
  • Certain antibiotics
  • Antidepressants
  • Chemotherapy agents
• Metabolic disorders
  • Thyroid dysfunction
  • Hyperlipidemia
• Psychological factors
  • Depression
  • Anxiety
  • Stress 5

Classification of Tinnitus

Subjective vs. Objective

• Subjective tinnitus - Only heard by the patient (most common)
• Objective tinnitus - Can be heard by an examiner (rare)
  • Usually caused by vascular abnormalities or middle ear muscle spasms 3

Pulsatile vs. Non-pulsatile

• Pulsatile tinnitus - Synchronous with heartbeat
  • Requires vascular imaging (CT angiography or MR angiography) 1
• Non-pulsatile tinnitus - Continuous sound without pulsation

Red Flags Requiring Further Investigation

• Unilateral tinnitus - Especially with asymmetric hearing loss (consider acoustic neuroma) 1, 2
• Pulsatile tinnitus - May indicate vascular pathology
• Sudden onset - Particularly when associated with hearing loss
• Focal neurological symptoms - Requires MRI brain with contrast 1
• Tinnitus with vertigo - May indicate Ménière's disease or other vestibular disorders 4

Diagnostic Approach

The American Academy of Otolaryngology-Head and Neck Surgery recommends:

1. Comprehensive audiologic evaluation for:

   • Unilateral tinnitus
   • Tinnitus present for ≥6 months
   • Tinnitus with hearing difficulties 1, 2

2. Imaging studies based on presentation:

   • MRI with contrast for unilateral tinnitus with asymmetric hearing loss
   • CT/MR angiography for pulsatile tinnitus
   • MRI brain with contrast for focal neurological findings 1

3. Otoscopic examination to identify:

   • Cerumen impaction
   • Middle ear effusion
   • Tympanic membrane perforation 1

Common Pitfalls to Avoid

• Failing to remove cerumen before assessment
• Overlooking non-otologic causes
• Not performing comprehensive audiologic evaluation for unilateral or persistent tinnitus
• Using unproven medications or supplements
• Ordering unnecessary imaging for non-concerning tinnitus presentations 1
• Making statements like "nothing can be done" which are inappropriate and unhelpful 6

Understanding the diverse causes of tinnitus is essential for proper diagnosis and management, with the ultimate goal of improving quality of life for patients experiencing this often distressing symptom.