Some Causes and Features of Hearing Loss
Cause* |
Common Features† |
Tests‡ |
External ear (conductive loss) |
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Obstruction (as caused by wax, a foreign body [object], an outer ear infection, or, rarely, a tumor) |
Visible during a doctor's examination |
A doctor's examination |
Middle ear (conductive loss) |
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Usually an eardrum that looks abnormal (seen during a doctor's examination) Sometimes dizziness, pain or fullness in the ear, or a discharge from the ear Often many previous ear infections |
Tympanometry (placement of a device in the ear to measure how well sound passes through the ear) Imaging for severe or recurrent infections |
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Often visible perforation of the eardrum, blood in the canal or behind the eardrum, or both In a person with an obvious recent injury |
A doctors' examination |
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Otosclerosis |
Often family members with similar hearing loss Hearing loss that slowly worsens Hearing loss that often starts in the 20s and 30s |
Tympanometry |
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Tumors (cancerous or not) |
Often visible tumor during a doctor's examination Hearing loss in only one ear |
CT or MRI using a contrast agent (gadolinium) |
Inner ear (sensory loss) |
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Genetic disorders |
Often family members with similar hearing loss Often accompanied by disease in other organ systems |
Genetic testing CT and/or MRI using a contrast agent (gadolinium) of the inner ear |
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Noise exposure |
Usually apparent by history Temporary or permanent hearing loss, depending on how loud the noise and how long the exposure are |
A doctor's examination |
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Older age (over 55 in men and over 65 in women) Progressive loss of hearing in both ears Normal neurologic examination |
A doctor's examination |
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Drugs that can damage the ear (ototoxic drugs), such as |
In a person who recently used a causative drug Hearing loss in both ears Sometimes dizziness and loss of balance |
A doctor's examination Sometimes blood drug levels |
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Infections, such as |
Obvious history of infection Hearing loss during or shortly after an infection |
A doctor's examination |
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Autoimmune disorders such as
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Joint inflammation and a rash Often in a person known to have the disorder |
Blood tests |
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Episodes of low-frequency hearing loss (typically in only one ear) Sense of fullness in the ear |
MRI using a contrast agent (gadolinium) to rule out tumor |
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Pressure changes (barotrauma, as may occur during diving) |
Deafness in one or both ears Sudden onset during causative activity (for example, scuba diving, rapid descent in airplane) or after a blow to the ear Sometimes accompanied by pain, an explosive sound, dizziness, or ringing in the ear |
Tympanometry Balance testing with electronystagmography (a test to record involuntary movements of the eye caused by a condition known as nystagmus) CT or MRI using a contrast agent (gadolinium) |
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Head injury (often with fracture of the base of the skull)§ |
In a person with an obvious recent severe injury Possibly dizziness or drooping facial muscles Sometimes fluid (bloody, blood-tinged, or clear) coming from the affected ear or blood behind the eardrum |
CT or MRI using a contrast agent (gadolinium) |
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Auditory neuropathy |
Good sound detection, but poor word understanding |
Specialized auditory testing MRI using a contrast agent (gadolinium) |
Nervous system (neural loss) |
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Tumors, such as
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Hearing loss in only one ear, often with tinnitus Often dizziness or vertigo, trouble with balance Sometimes drooping facial muscles and/or numbness of the face and taste abnormalities |
MRI using a contrast agent (gadolinium) |
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Demyelinating disorders, such as multiple sclerosis |
Hearing loss in only one ear Sometimes weakness or numbness that comes and goes and that occurs in different parts of the body |
MRI of the brain and spinal cord using a contrast agent (gadolinium) Sometimes a spinal tap (lumbar puncture) |
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* Causes in each group are listed in approximate order of frequency. |
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† Features include symptoms and the results of the doctor's examination. Features mentioned are typical but not always present. |
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‡ Although a doctor's examination with audiologic testing is always done, it is only mentioned in this column if the diagnosis can sometimes be made only by the doctor's examination and audiologic testing without any additional testing. In other words, additional tests may not be needed. |
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§ Mixed conductive and sensorineural loss may be present. |
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CT = computed tomography; MRI = magnetic resonance imaging. |
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