What are the causes of tinnitus (ear ringing)?

Causes of Ear Ringing (Tinnitus)

Sensorineural hearing loss is the single most common underlying cause of tinnitus, particularly in patients with bothersome tinnitus and no obvious ear pathology. 1, 2

Primary Auditory System Causes

The vast majority of tinnitus originates from dysfunction within the auditory system itself:

• Age-related hearing loss (presbycusis) represents progressive degeneration of cochlear hair cells, typically affecting high-frequency perception first, and is the most common cause in older adults 1, 2
• Noise-induced hearing loss from occupational or recreational exposure (concerts, firearms, machinery) causes permanent damage to cochlear structures 1
• Cochlear synaptopathy ("hidden hearing loss") triggers irreversible degeneration of auditory nerve fibers without affecting outer hair cells or causing detectable threshold shifts on standard audiometry, leading to difficulty understanding speech in noise despite "normal" hearing tests 1, 2
• Ototoxic medications including certain antibiotics, chemotherapy agents, and high-dose aspirin can damage cochlear structures 1, 3

Secondary Otologic Causes Requiring Identification

These conditions produce tinnitus but have specific underlying pathology that may be treatable:

• Cerumen impaction is a simple, reversible cause identifiable on otoscopic examination 4, 2
• Middle ear infection or effusion can cause conductive hearing loss with associated tinnitus 4, 3
• Otosclerosis causes conductive hearing loss that triggers tinnitus 1, 2
• Menière's disease presents with episodic vertigo, fluctuating hearing loss, and tinnitus 2, 3
• Sudden sensorineural hearing loss requires urgent evaluation and treatment 1, 2

Vascular Causes (Pulsatile Tinnitus)

Pulsatile tinnitus—a repetitive sound synchronizing with heartbeat—has an identifiable structural or vascular cause in over 70% of cases and requires urgent imaging evaluation. 2 Life-threatening causes include:

• Arterial dissection and fibromuscular dysplasia of carotid arteries 1
• Dural arteriovenous fistulas and arteriovenous malformations 1, 5
• Carotid artery atherosclerosis with stenosis 4, 5
• Paragangliomas (glomus tumors) and other vascular middle ear tumors 1, 5
• Idiopathic intracranial hypertension 1, 2
• Venous sinus abnormalities including transverse sinus stenosis, sigmoid sinus diverticulum or dehiscence 1

Structural/Bony Abnormalities

• Superior semicircular canal dehiscence creates abnormal sound transmission 1
• High jugular bulb or sigmoid sinus wall dehiscence can cause pulsatile symptoms 1
• Paget disease affecting the temporal bone 1

Neurologic Causes

• Vestibular schwannoma (acoustic neuroma) almost always causes unilateral tinnitus with asymmetric hearing loss 4, 3
• Cerebellopontine angle masses and auditory pathway lesions 4
• Neurodegeneration can trigger tinnitus through central auditory pathway dysfunction 1
• Spontaneous intracranial hypotension 1
• Temporal bone fracture or head trauma with vascular injury 4

Psychogenic and Comorbid Factors

• Anxiety and depression are both risk factors for developing tinnitus and consequences that worsen its impact 1, 6
• Severe psychiatric illness with tinnitus carries suicide risk and requires prompt intervention 4, 1

Critical Clinical Pitfalls to Avoid

Do not dismiss bilateral tinnitus as benign without proper evaluation. While bilateral, symmetric, non-pulsatile tinnitus without neurologic deficits typically represents presbycusis or noise-induced hearing loss and does not require imaging 4, 2, you must still perform:

• Targeted otoscopic examination to identify cerumen, infection, or retrotympanic masses 4, 2
• Comprehensive audiologic testing within 4 weeks for any persistent tinnitus 2
• Assessment for medication causes, as many drugs are ototoxic 1

Unilateral or asymmetric tinnitus demands investigation for acoustic neuroma. This presentation requires MRI of the internal auditory canals with contrast to exclude vestibular schwannoma 4, 3

Pulsatile tinnitus is vascular until proven otherwise. This requires CT angiography/venography or MR angiography to identify potentially life-threatening vascular abnormalities 4, 2

Tinnitus that wakes a patient from sleep is highly unusual and should immediately raise suspicion for objective tinnitus with vascular or neuromuscular etiology, particularly pulsatile tinnitus from vascular abnormalities 2