tinitus dd

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Tinnitus is the perception of sound (ringing, buzzing, hissing, clicking) without an external source. The differential diagnosis is broad, spanning otologic, vascular, neurologic, and systemic causes.

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tinnitus differential diagnosis etiology

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Tinnitus - Differential Diagnosis

Classification Framework

Tinnitus is first classified along three axes, as this guides the entire workup:

Axis	Types
Subjective vs. Objective	Subjective (heard only by patient, ~98.5%) vs. Objective (audible to examiner, ~1.5%)
Pulsatile vs. Nonpulsatile	Pulsatile (rhythmic, pulse-synchronous) vs. Nonpulsatile (constant ringing/buzzing/hissing)
Primary vs. Secondary	Primary (idiopathic, with or without SNHL) vs. Secondary (identifiable underlying cause)

Subjective nonpulsatile tinnitus is by far the most common type, representing approximately 90% of all otolaryngology referrals. - Cummings Otolaryngology Head and Neck Surgery, p. 2951

DD: Subjective Nonpulsatile Tinnitus

Otologic (Inner Ear)

Sensorineural hearing loss (SNHL) - most common cause overall; bilateral tinnitus + symmetric SNHL typically requires no further imaging
Presbycusis (age-related hearing loss)
Noise-induced hearing loss (NIHL) - acoustic trauma (single event or chronic occupational)
Meniere disease - classic triad: episodic vertigo + fluctuating low-frequency SNHL + tinnitus (often roaring quality)
Labyrinthitis (viral or bacterial)
Sudden sensorineural hearing loss - medical emergency; requires urgent audiogram and treatment

Otologic (Middle Ear)

Otosclerosis - conductive or mixed hearing loss + tinnitus
Ossicular chain abnormalities / tympanic membrane perforation
Cholesteatoma
Otitis media (acute or chronic)
Herpes zoster oticus (Ramsay Hunt syndrome)

Otologic (External Ear)

Cerumen impaction / canal occlusion
Otitis externa

Retrocochlear / Neurologic

Vestibular schwannoma (acoustic neuroma) - unilateral tinnitus + asymmetric SNHL is the red flag; requires MRI with gadolinium of IAC/CPA
Other cerebellopontine angle tumors (meningioma, epidermoid cyst, glomus jugulare)
Multiple sclerosis
Charcot-Marie-Tooth disease
Epilepsy / migraine
Basilar skull fracture / whiplash injury
Meningitic effects

Ototoxic Medications

A major and reversible cause; always review the medication list:

Aminoglycosides (gentamicin, tobramycin)
Aspirin / NSAIDs (dose-dependent, often reversible)
Loop diuretics (furosemide, ethacrynic acid)
Platinum-based antineoplastics (cisplatin - irreversible cochlear damage)
Tricyclic antidepressants
Quinine / antimalarials
Heavy metals
Oral contraceptives

Metabolic / Endocrine

Hypothyroidism or hyperthyroidism (hypermetabolic state increases cochlear blood flow)
Diabetes mellitus / hyperinsulinemia
Hyperlipidemia
Vitamin deficiencies (B12, zinc)
Anemia (increased cardiac output)
Pregnancy

Autoimmune

Systemic lupus erythematosus (SLE)
Systemic sclerosis
Rheumatoid arthritis
Autoimmune inner ear disease

Psychological / Psychiatric

Anxiety disorder
Depression
These are associated conditions that amplify tinnitus perception through altered central auditory processing

Musculoskeletal

Temporomandibular joint (TMJ) disorder - often unilateral, clicking, altered by jaw movement

Social Habits

Caffeine, nicotine, alcohol, cocaine, marijuana (can worsen or precipitate tinnitus)

DD: Pulsatile Tinnitus (Arterial vs. Venous)

Pulsatile tinnitus - described as rhythmic, heartbeat-like sound - requires dedicated vascular imaging (CTA/CTV of head and neck is the typical first-line study). About 20-30% of pulsatile tinnitus cases have a significant imaging abnormality. - Cummings Otolaryngology, p. 2953

Arterial Causes (Objective or Subjective)

Atherosclerotic carotid artery disease - most common arterial pulsatile tinnitus cause; bruit may be audible
Arteriovenous malformation (AVM) / dural arteriovenous fistula
Carotid-cavernous fistula
Aneurysm (intracranial or extracranial)
Persistent stapedial artery (congenital anomaly)
Fibromuscular dysplasia of the carotid
Carotid artery dissection
Hypermetabolic states (hyperthyroidism, anemia, pregnancy) - increased arterial flow

Venous Causes

Idiopathic intracranial hypertension (IIH) / pseudotumor cerebri - often bilateral pulsatile tinnitus in obese young women; venous hum that resolves with digital compression of the ipsilateral internal jugular vein
Dehiscent jugular bulb (high-riding jugular bulb)
Jugular vein stenosis or thrombosis
Idiopathic venous hum

Vascular Tumors

Glomus tympanicum - pulsatile tinnitus + reddish-blue retrotympanic mass on otoscopy
Glomus jugulare - pulsatile tinnitus + lower cranial nerve palsies (IX, X, XI)
Paraganglioma

Semicircular Canal / Inner Ear Dehiscence

Superior semicircular canal dehiscence (SSCD) - autophony, pulsatile or nonpulsatile tinnitus, Tullio phenomenon; diagnosed by high-resolution CT

DD: Objective Tinnitus (Rare, ~1.5% of cases)

These have an identifiable, audible sound source:

Palatal myoclonus - rhythmic clicking from levator/tensor veli palatini spasms; audible as clicking
Stapedial muscle myoclonus - rapid, irregular clicking
Patulous Eustachian tube - autophony, breath-synchronous, worsened upright/weight loss
Vascular tumors (glomus, AVM) - as above
Arnold-Chiari malformation type I - associated with intracranial venous hypertension

Red Flags Requiring Urgent/Prompt Workup

Red Flag	Action
Sudden hearing loss + tinnitus	Urgent audiogram + same-day steroids
Unilateral tinnitus + asymmetric SNHL	MRI brain/IAC with gadolinium (r/o vestibular schwannoma)
Pulsatile tinnitus	CTA/CTV head and neck
Retrotympanic mass on otoscopy	CT temporal bone
Focal neurologic deficit + tinnitus	Urgent MRI brain
Unilateral tinnitus alone	MRI (low yield but indicated per AAO-HNS guidelines)

Diagnostic Approach Summary

History - laterality, quality (ringing/clicking/pulsatile), onset, associated hearing loss, vertigo, medications, noise exposure, cardiovascular risk factors
Otoscopy - look for retrotympanic mass, cerumen, perforation, cholesteatoma
Audiogram - mandatory for all; defines symmetric vs. asymmetric SNHL
Tuning fork tests (Weber, Rinne) - bedside differentiation of conductive vs. sensorineural
Auscultation - periauricular, neck, chest for bruit/murmur
Imaging - reserved for: unilateral, pulsatile, asymmetric SNHL, or neurologic deficit
Labs - TSH, CBC, lipids, fasting glucose if metabolic cause suspected

The most common cause remains idiopathic primary tinnitus associated with bilateral SNHL, which does not require imaging. - Textbook of Family Medicine 9e, p. 546

Sources: Cummings Otolaryngology Head and Neck Surgery (Chapter 153); Textbook of Family Medicine 9e (Chapter 18); related review: Pulsatile Tinnitus: Differential Diagnosis and Approach to Management - Wang H et al., Curr Pain Headache Rep 2024.

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