What are the most common causes of tinnitus?

Most Common Causes of Tinnitus

Sensorineural hearing loss (SNHL) is the single most common underlying cause of tinnitus, particularly in patients with bothersome tinnitus and no obvious ear pathology. 1

Primary Causes

Age-related hearing loss (presbycusis) and noise-induced hearing loss are the two dominant etiologies that drive the majority of tinnitus cases in clinical practice. 1

Sensorineural Hearing Loss

• SNHL accounts for 70-80% of subjective tinnitus cases and represents the primary mechanism of auditory system dysfunction leading to phantom sound perception. 1
• Presbycusis (age-related hearing loss) increases dramatically with age, with tinnitus prevalence rising from 1.6% in adults aged 18-44 years to 9.0% in those over 60 years. 1
• Noise exposure—both occupational (machinery, construction) and recreational (concerts, firearms)—causes irreversible cochlear damage and is a major preventable cause. 1
• Cochlear synaptopathy ("hidden hearing loss") triggers auditory nerve fiber degeneration without affecting outer hair cells, leading to difficulty understanding speech in noise and tinnitus. 1

Secondary Otologic Causes

• Sudden sensorineural hearing loss requires prompt identification as it represents an otologic emergency. 1
• Menière's disease presents with episodic vertigo, fluctuating hearing loss, and tinnitus. 2
• Otosclerosis causes conductive hearing loss that can trigger tinnitus. 1
• Cerumen impaction and middle ear effusion are simple, reversible causes that must be excluded on examination. 3

Vascular Causes (Pulsatile Tinnitus)

When tinnitus is pulsatile (synchronous with heartbeat), the differential diagnosis shifts entirely to vascular and structural abnormalities, which are identifiable in over 70% of cases. 4

Most Common Vascular Etiologies

• Atherosclerotic carotid artery disease is the most frequent cause of pulsatile tinnitus, accounting for 17.5% of cases due to turbulent flow. 4
• Idiopathic intracranial hypertension (pseudotumor cerebri) is the second most common cause, particularly in young overweight women with headaches. 4
• Paragangliomas (glomus tumors) account for 16% of pulsatile tinnitus cases and appear as vascular retrotympanic masses on otoscopy. 4

Life-Threatening Vascular Causes

• Dural arteriovenous fistulas account for 8% of cases and can lead to hemorrhagic or ischemic stroke if untreated—this is a critical diagnosis that cannot be missed. 4
• Arterial dissection requires urgent identification as it represents an acute vascular emergency. 4
• Arteriovenous malformations carry a 2-3% annual hemorrhage risk with 10-30% mortality from first hemorrhage. 4

Venous and Structural Causes

• Sigmoid sinus diverticulum or dehiscence is commonly associated with intracranial hypertension. 4
• Jugular bulb abnormalities (high-riding jugular bulb or dehiscence of the sigmoid plate) can cause pulsatile tinnitus. 4
• Superior semicircular canal dehiscence allows transmission of vascular sounds into the inner ear. 4

Medication-Induced Tinnitus

Ototoxic medications are an important iatrogenic cause that must be identified through careful medication history. 1 Common culprits include aminoglycoside antibiotics, loop diuretics, chemotherapy agents (cisplatin), and high-dose aspirin. 5, 6

Selective serotonin reuptake inhibitors (SSRIs) like escitalopram can cause tinnitus as either a side effect during use or a withdrawal symptom. 7

Neurologic and Psychogenic Factors

• Anxiety and depression are both risk factors for developing tinnitus and consequences of severe tinnitus, creating a bidirectional relationship. 1
• Neurodegeneration represents a neurologic cause of tinnitus through central auditory pathway dysfunction. 1
• Patients with tinnitus accompanied by severe anxiety or depression require prompt identification and intervention due to increased suicide risk. 1

Critical Clinical Pitfalls

• Dismissing pulsatile tinnitus as benign is dangerous—it almost always requires imaging evaluation due to identifiable causes in >70% of cases. 4
• Missing dural arteriovenous fistula can be catastrophic, as it may present with isolated pulsatile tinnitus before hemorrhage. 4
• Overlooking intracranial hypertension in young overweight women with headaches can lead to permanent vision loss. 4
• Failing to perform adequate otoscopic examination delays diagnosis of vascular retrotympanic masses like paragangliomas. 4
• Unilateral tinnitus with asymmetric hearing loss should raise suspicion for acoustic neuroma (vestibular schwannoma) and warrants comprehensive audiologic evaluation and imaging. 1, 8