What causes tinnitus (ringing in the ears) in an adult with no prior history of ear problems?

What Causes Ringing in the Ears

Sensorineural hearing loss is the single most common underlying cause of tinnitus in adults, accounting for the majority of cases where no obvious ear pathology is present. 1

Primary Mechanisms

Auditory system dysfunction drives most tinnitus cases through several pathways:

• Sensorineural hearing loss (SNHL) represents the most frequent etiology, where damage to the inner ear or auditory nerve creates abnormal neural activity perceived as phantom sound 1
• Noise exposure (occupational or recreational) damages cochlear structures and triggers tinnitus, often accompanied by hearing loss 1
• Presbycusis (age-related hearing loss) is extremely common, with tinnitus prevalence increasing from 1.6% in adults aged 18-44 years to 9.0% in those over 60 years 1
• Cochlear synaptopathy ("hidden hearing loss") causes irreversible auditory nerve fiber degeneration without affecting standard hearing tests, leading to tinnitus and difficulty understanding speech in noisy environments 1

Secondary Causes Requiring Identification

Beyond hearing loss, several specific conditions must be ruled out:

• Otosclerosis causes conductive hearing loss that can trigger tinnitus 1
• Menière's disease presents with episodic vertigo, fluctuating hearing loss, and tinnitus 1
• Sudden sensorineural hearing loss requires urgent evaluation and treatment 1
• Ototoxic medications (certain antibiotics, chemotherapy agents) can damage cochlear structures 1

Vascular and Structural Causes (Pulsatile Tinnitus)

If the tinnitus is pulsatile (synchronous with heartbeat), this fundamentally changes the diagnostic approach because over 70% of cases have an identifiable structural or vascular cause, some life-threatening:

• Atherosclerotic carotid artery disease is the most frequent cause of pulsatile tinnitus (17.5% of cases), resulting from turbulent blood flow 2
• Idiopathic intracranial hypertension is the second most common cause, particularly in young overweight women, and can lead to vision loss if missed 2
• Dural arteriovenous fistulas (8% of pulsatile tinnitus cases) represent a life-threatening condition that can lead to hemorrhagic or ischemic stroke if untreated 2
• Arterial dissection requires urgent identification due to stroke risk 2
• Paragangliomas (glomus tumors) account for 16% of pulsatile tinnitus cases and appear as vascular retrotympanic masses on otoscopy 2
• Sigmoid sinus abnormalities (diverticulum or dehiscence) commonly associate with intracranial hypertension 2
• Superior semicircular canal dehiscence allows transmission of vascular sounds into the inner ear 2

Neurologic and Psychogenic Factors

• Neurodegeneration can contribute to central auditory pathway dysfunction causing tinnitus 1
• Anxiety and depression are psychogenic factors that both contribute to and result from tinnitus, creating a bidirectional relationship 1
• Intracranial hypertension can cause tinnitus through venous sinus compression 1

Critical Clinical Distinctions

The quality and laterality of tinnitus provide diagnostic clues:

• Unilateral tinnitus has higher likelihood of identifiable structural cause and warrants imaging evaluation 2
• Bilateral, symmetric, non-pulsatile tinnitus without localizing features typically does not require imaging 2
• Objective tinnitus (audible to examiner) is rare and strongly suggests vascular pathology requiring immediate workup 2
• Typewriter tinnitus (paroxysmal clicking sounds) results from neurovascular compression of the cochlear nerve and responds remarkably well to carbamazepine 3

Common Pitfalls to Avoid

• Dismissing pulsatile tinnitus as benign without imaging is dangerous, as treatable and life-threatening causes are common 2
• Missing dural arteriovenous fistula can result in catastrophic hemorrhage, requiring high index of suspicion and appropriate vascular imaging 2
• Overlooking intracranial hypertension in young overweight women with headaches can lead to permanent vision loss 2
• Inadequate otoscopic examination can delay diagnosis of vascular retrotympanic masses like paragangliomas 2
• Failing to identify severe anxiety or depression is critical, as patients with tinnitus accompanied by these conditions have increased suicide risk and require prompt intervention 1

Age and Risk Factors

• Advanced age is the strongest demographic risk factor, with prevalence dramatically increasing after age 60 1
• Occupational and recreational noise exposure (concerts, firearms, industrial settings) significantly increases risk 1
• Approximately 10-15% of adults experience tinnitus, with around 20% requiring clinical intervention 1