Causes of Tinnitus

Tinnitus is not a disease in and of itself, but rather a symptom of some other underlying health condition. In most cases, tinnitus is a sensorineural reaction in the brain to damage in the ear and auditory system. While tinnitus is most often triggered by hearing loss, there are roughly 200 different health disorders that can generate tinnitus as a symptom. Below is a list of the most common catalysts for tinnitus.

Please note: Tinnitus, by itself, does not necessarily indicate any one of the items listed below. Patients experiencing tinnitus should see their physician or a hearing health professional for a full examination to diagnose the underlying cause of symptoms. In some cases, resolving the root cause will alleviate the perception of tinnitus.

Hearing Loss – Causes of Tinnitus

Sensorineural hearing loss is, by far, the most common cause of tinnitus. Some researchers believe that subjective tinnitus cannot exist without some prior loss of hearing. The underlying hearing loss can be the result of:

• Age-related hearing loss (presbycusis) – Hearing often deteriorates as people get older, typically starting around the age of 60. This form of hearing loss tends to be bilateral (in both ears) and involve the sensory loss of high-frequency sounds. Age-related hearing loss explains, in part, why tinnitus is so prevalent among seniors.
• Noise-induced hearing loss – Exposure to loud noises, either in a single traumatic experience or over time, can damage the auditory system and result in hearing loss. Traumatic noise exposure can happen at work (e.g. loud machinery), at play (e.g. loud sporting events, concerts, recreational activities), and/or by accident (e.g. a backfiring engine.) Noise induced hearing loss is sometimes unilateral (one ear only) and typically causes patients to lose hearing around the frequency of the triggering sound trauma. It also tends to accumulate over time, so even moderate sound exposure can sometimes lead to permanent hearing damage.

It is important to note that existing hearing loss is sometimes not directly observable by the patient, who may not perceive any lost frequencies. But this this does not mean that hearing damage has not been done. A trained audiologist or other hearing health professional can perform sensitive audiometric tests to precisely measure the true extent of hearing loss.

The exact biological process by which hearing loss leads to tinnitus is still being investigated by researchers. However, we do know that the sensory loss of certain sound frequencies leads to specific changes in how the brain processes sound. In short, as the brain receives less external stimuli around a specific frequency, it begins to adapt and change. Tinnitus may be the brain’s way of filling in the missing sound frequencies it no longer receives from the auditory system.

Obstructions in the Middle Ear – Causes of Tinnitus

Blockages in the ear canal can cause pressure to build up in the inner ear, affecting the operation of the ear drum. Moreover, objects directly touching the ear drum can irritate the organ and cause the perception of tinnitus symptoms. Common obstructions include:

• Excessive ear wax (ceruminosis)
• Head congestion
• Loose hair from the ear canal
• Dirt or foreign objects

In many cases, the removal of the blockage will alleviate tinnitus symptoms. However, in some situations, the blockage may have caused permanent damage that leads to chronic tinnitus.

Head and Neck Trauma – Causes of Tinnitus

Severe injury to the head or neck can cause nerve, blood flow, and muscle issues that result in the perception of tinnitus. Patients who ascribe their condition to head and neck trauma often report higher tinnitus volume and perceived burden, as well as greater variability in both sound, frequency, and location of their tinnitus.

Tinnitus related to head, neck, or dental issues is sometimes referred to as somatic tinnitus. (“Somatic” derives from the Greek somatikos, meaning “of the body.”)

Temporomandibular Joint Disorder – Causes Of Tinnitus

Another example of somatic tinnitus is that caused by temperomandibular joint disorder. The temporomandibular joint (TMJ) is where the lower jaw connects to the skull, and is located in front of the ears. Damage to the muscles, ligaments, or cartilage in the TMJ can lead to tinnitus symptoms. The TMJ is adjacent to the auditory system and shares some ligaments and nerve connections with structures in the middle ear.

Tinnitus patients with a TMJ disorder will experience pain in the face and/or jaw, limited ability to move the jaw, and regular popping sounds while chewing or talking.  A dentist, craniofacial surgeon, or other oral health professional can appropriately diagnose and often fix TMJ issues. In many scenarios, fixing the TMJ disorder will alleviate tinnitus symptoms.

Sinus Pressure and Barometric Trauma – Causes of Tinnitus

Nasal congestion from a severe cold, flu, or sinus infection can create abnormal pressure in the middle ear, impacting normal hearing and causing tinnitus symptoms.

Acute barotrauma, caused by extreme or rapid changes in air or water pressure, can also damage the middle and inner ear. Potential sources of barotrauma include:

• Diving / Snorkeling / Scuba
• Flying (only during extreme, abnormal elevation changes; normal commercial air travel is generally safe)
• Concussive explosive blasts

Traumatic Brain Injury (TBI) – Causes of Tinnitus

Traumatic brain injury, caused by concussive shock, can damage the brain’s auditory processing areas and generate tinnitus symptoms. TBI is one of the major catalysts for tinnitus in military and veteran populations. Nearly 60% of all tinnitus cases diagnosed by the U.S. Veterans Administration are attributable to mild-to-severe traumatic brain injuries.

Ototoxic Drugs – Causes of Tinnitus

Tinnitus is a potential side-effect of many prescription medications. However, in most cases and for most drugs, tinnitus is an acute, short-lived side-effect; if the patient stops taking the medication, the tinnitus symptoms typically receed. However, there are some ototoxic drugs known to cause more permanent tinnitus symptoms. These include:

• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
• Certain antibiotics
• Certain cancer medications
• Water pills and diuretics
• Quinine-based medications

If you are worried about tinnitus as a side effect of your medications, please consult your subscribing physician or pharmacist. You should not stop taking any medication without first consulting with your healthcare provider. The risks of stopping a medication may far exceed any potential benefit.

Other Diseases & Medical Conditions – Causes of Tinnitus

• Tinnitus is a reported symptom of the following medical conditions:
• Metabolic Disorders: Hypothyroidism, Hyperthyroidism, Anemia
• Autoimmune Disorders: Lyme Disease, Fibromyalgia
• Blood Vessel Disorders: High Blood Pressure, Atherosclerosis
• Psychiatric Disorders: Depression, Anxiety, Stress
• Vestibular Disorders: Ménière’s Disease,Thoracic Outlet Syndrome, Otosclerosis
• Tumor-Related Disorders (very rare): Acoustic Neuroma, Vestibular Schwannoma, other tumorous growths

A person experiencing tinnitus should not assume that he/she has one of the medical conditions listed above. Only a trained healthcare provider can appropriately diagnose the underlying cause of tinnitus.