Tinnitus is the perception of sound in the absence of an objective internal or external source. Tinnitus is a symptom, not a disease, and although it is typically not associated with a dangerous condition, it can significantly affect quality of life. Tinnitus is a common problem among adults in the United States, with an estimated prevalence of 10% to 15% and peak incidence between 60 and 69 years of age.^1–3 At least 20% of people diagnosed with tinnitus will seek clinical intervention.⁴ The etiology of primary tinnitus is often unclear, but most cases are associated with sensorineural hearing loss (SNHL). Secondary tinnitus results from sound generated by a source near the ear or referred to the ear, and is rare, accounting for less than 1% of tinnitus cases.^5,6 Vascular and neuromuscular etiologies are the more common causes of secondary tinnitus.^5,7 Guidelines recommend a standard approach to history and physical examination that can begin the process of determining the etiology of the tinnitus, followed by audiometric testing and imaging, laboratory studies, and other testing as appropriate.^8,9

Etiology

For this review, tinnitus is categorized as primary and secondary. Primary tinnitus is the more common of the two categories. It is idiopathic, and most cases are associated with SNHL, including presbycusis and noise-related hearing loss. The exact pathophysiology of primary tinnitus is often unclear and is likely multifactorial. It is thought to be a phantom sensation from abnormal neural activity in the ear, the auditory nerve, or central nervous system.¹⁰ Patients with primary tinnitus that is not bothersome do not require further intervention.⁸ Secondary tinnitus has an identifiable cause.⁸ Table 1 lists the causes of secondary tinnitus.^6,11–16 Many medications are associated with ototoxicity, resulting in tinnitus or hearing loss; the most commonly used are listed in Table 2.^17–19 Tinnitus is also a common accompanying symptom of Meniere disease and vestibular schwannoma, previously known as acoustic neuroma. Tinnitus is strongly associated with depression; the presence of tinnitus can worsen depressive symptoms and contribute to suicidal ideation.^8,20

Diagnosis

When a patient presents with tinnitus, the clinician's main goal is to identify causes that can be treated, or that may be dangerous. Figure 1 outlines elements of the initial evaluation and management of tinnitus.^{5,8,9,13,17–19,21–26}

HISTORY AND PHYSICAL EXAMINATION

A focused, detailed history and physical examination are the primary tools for diagnosing tinnitus, distinguishing benign from dangerous causes, and determining potential treatment options.^8,9 Initial triage involves identifying characteristics of the patient's tinnitus that warrant urgent evaluation: pulsatile, associated with neurologic abnormalities, asymmetric or unilateral symptoms, and asymmetric hearing loss. Although it is much less common, pulsatile tinnitus should raise suspicion for underlying cardiovascular disease and intracranial vascular abnormality (e.g., vascular tumor), increased intracranial pressure, or neoplasm.¹¹