Ringing in the ears (tinnitus) is noise originating in the ear rather than in the environment. It is a symptom and not a specific disease. Tinnitus is very common—10 to 15% of people experience it to some degree.
The noise heard by people with tinnitus may be a buzzing, ringing, roaring, whistling, or hissing sound and is often associated with hearing loss Hearing Loss Worldwide, about half a billion people (almost 8% of the world's population) have hearing loss. More than 15% of people in the United States have some degree of hearing loss that affects their... read more 
. Some people hear more complex sounds that may be different at different times. These sounds are more noticeable in a quiet environment and when people are not concentrating on something else. Thus, tinnitus tends to be most disturbing to people when they are trying to sleep. However, the experience of tinnitus is highly individual. Some people are very disturbed by their symptoms, whereas others find them quite bearable.
Subjective tinnitus is by far the most common type. It is caused by abnormal activity in the part of the brain responsible for processing sound (auditory cortex). Doctors do not fully understand how this abnormal activity develops.
Objective tinnitus is much less common. It represents actual noise created by structures near the ear. Other people can sometimes hear the sounds of objective tinnitus if they listen closely.
Causes of Ear Ringing or Buzzing
Subjective tinnitus
More than 75% of ear-related disorders include tinnitus as a symptom, and people who have hearing loss, regardless of cause, often develop tinnitus. The most common causes of subjective tinnitus include
Exposure to loud noises or explosions (acoustic trauma)
Other causes of tinnitus include middle ear infections Otitis Media (Acute) Acute otitis media is a bacterial or viral infection of the middle ear. Acute otitis media often occurs in people with a cold or allergies. The infected ear is painful. Doctors examine the eardrum... read more 
, disorders that block the ear canal Objects in the Ear Objects in the ear can be removed by flushing the ear canal with sterile water or saline or using suction, forceps, or other tools. If the foreign body cannot easily be removed, a referral to... read more (such as an external ear infection [external otitis], excessive ear wax, or foreign bodies), problems with the eustachian tube (which connects the middle ear and the back of the nose) due to allergies or other causes of obstruction, otosclerosis (a disorder of excess bone growth in the middle ear), and temporomandibular disorders Temporomandibular Disorders The temporomandibular joints are the connections between the temporal bones of the skull and the lower jawbone (mandible). There are two temporomandibular joints, one on each side of the face... read more . An uncommon but serious cause is a vestibular schwannoma Vestibular Schwannoma A vestibular schwannoma (also known as an acoustic neuroma) is a noncancerous (benign) tumor that originates in the cells that wrap around the vestibular nerve (Schwann cells). These tumors... read more 
, a noncancerous (benign) tumor of part of the nerve leading from the inner ear.
Objective tinnitus
Objective tinnitus usually involves noise from blood vessels near the ear. In such cases, the sound comes with each beat of the pulse (pulsatile). Causes include
Turbulent flow through the carotid artery or jugular vein
Certain middle ear tumors that are rich in blood vessels
Malformed blood vessels of the membrane covering the brain
The most common noise is the sound of rapid or turbulent blood flow in major vessels of the neck. This abnormal blood flow may occur because of a reduced red blood cell count ( anemia Overview of Anemia Anemia is a condition in which the number of red blood cells is low. Red blood cells contain hemoglobin, a protein that enables them to carry oxygen from the lungs and deliver it to all parts... read more ) or a blockage of the arteries ( atherosclerosis Atherosclerosis Atherosclerosis is a condition in which patchy deposits of fatty material (atheromas or atherosclerotic plaques) develop in the walls of medium-sized and large arteries, leading to reduced or... read more 
) and may be worsened in people with poorly controlled high blood pressure ( hypertension High Blood Pressure High blood pressure (hypertension) is persistently high pressure in the arteries. Often no cause for high blood pressure can be identified, but sometimes it occurs as a result of an underlying... read more 
). Some small tumors of the middle ear called glomus tumors are rich in blood vessels. Although the tumors are small, they are very near the sound-receiving structures of the ear, and blood flow through them can sometimes be heard (only in one ear). Sometimes, blood vessel malformations that involve abnormal connections between arteries and veins (arteriovenous malformations) develop in the membrane covering the brain (the dura). If these malformations are near the ear, the person sometimes can hear blood flowing through them.
Less commonly, spasms of muscles of the palate or the small muscles of the middle ear cause clicking sounds. These sounds do not follow the beat of the pulse. Such spasms often have no known cause but may be due to tumors, head injury, or diseases that affect the covering of nerves (for example, multiple sclerosis Multiple Sclerosis (MS) In multiple sclerosis, patches of myelin (the substance that covers most nerve fibers) and underlying nerve fibers in the brain, optic nerves, and spinal cord are damaged or destroyed. The cause... read more ).
Evaluation of Ear Ringing or Buzzing
Not all tinnitus requires evaluation by a doctor. The following information can help people decide whether a doctor's evaluation is needed and help them know what to expect during the evaluation.
Warning signs
Certain symptoms and characteristics are cause for concern. They include
Tinnitus in only one ear
Any neurologic symptoms (other than hearing loss), particularly difficulty with balance or walking, but also vertigo or difficulty seeing, speaking, swallowing, and/or talking
When to see a doctor
People with warning signs should see a doctor right away. People without warning signs in whom tinnitus recently developed should call their doctor, as should people with pulsatile tinnitus. Most people with tinnitus and no warning signs have had tinnitus for a long time but should see their doctor about it if they have not already done so.
What the doctor does
In people with tinnitus, doctors first ask questions about the person's symptoms and medical history. Doctors then do a physical examination. What they find during the history and physical examination may suggest a cause of the tinnitus and the tests that may need to be done (see table Some Causes and Features of Tinnitus Some Causes and Features of Tinnitus 
).
During the medical history, doctors ask about the following:
The nature of the tinnitus, including whether it is in one or both ears and whether it is constant or pulsatile
Whether the person has any neurologic symptoms
Whether the person has been exposed to loud noise or to drugs that can affect the ears
During the physical examination, doctors focus on examining the ears (including hearing) and the neurologic system. They also listen with a stethoscope over and near the person's ear and on the neck for sounds of objective tinnitus.
Testing
Possible tests for people with tinnitus include
Formal hearing test (including tympanometry Testing
)
Most people should have a formal hearing test done by either the doctor or a hearing specialist (audiologist). People with tinnitus in only one ear and hearing loss should have gadolinium-enhanced magnetic resonance imaging (MRI). People with pulsatile tinnitus often require magnetic resonance angiography ( MRA Magnetic resonance angiography (MRA) In magnetic resonance imaging (MRI), a strong magnetic field and very high frequency radio waves are used to produce highly detailed images. MRI does not use x-rays and is usually very safe... read more 
), computerized tomography angiography (CTA), or conventional angiography.
Treatment of Ear Ringing or Buzzing
Attempts to identify and treat the disorder causing tinnitus are often unsuccessful. However, correcting any hearing loss (for example, with a hearing aid Hearing Aids Many causes of hearing loss have no cure. In these cases, treatment involves compensating for the hearing loss as much as possible. Most people with moderate to severe loss use hearing aids... read more ) relieves tinnitus in about half of people.
Treatment of stress and other mental conditions (such as depression) may help. Many people are reassured if they learn that their tinnitus is not caused by a serious disorder. Caffeine and other stimulants can worsen tinnitus, so people should try to avoid these.
Various techniques can help make tinnitus tolerable, although the ability to tolerate it varies from person to person. Many people find that background sound helps mask the tinnitus and helps them fall asleep. Some people play background music. Other people use a tinnitus masker, which is a device worn like a hearing aid that produces a constant level of neutral sounds. For the profoundly deaf, an implant in the cochlea Cochlear Implants Many causes of hearing loss have no cure. In these cases, treatment involves compensating for the hearing loss as much as possible. Most people with moderate to severe loss use hearing aids... read more (the organ of hearing) may reduce tinnitus but is only done for people with severe to profound hearing loss in both ears. If these standard techniques are not helpful, people may want to seek treatment in clinics that specialize in the treatment of tinnitus.
Key Points about Ear Ringing or Buzzing
Most tinnitus is due to causes that are not dangerous, for example, exposure to loud noise, aging, Meniere disease, and use of certain drugs.
In many cases, the cause is unknown.
Findings that are of concern include tinnitus accompanied by any neurologic symptoms and tinnitus in only one ear (particularly when accompanied by hearing loss, dizziness, and/or balance difficulty).
Tinnitus rarely can be stopped, but certain techniques help people manage their symptoms effectively.
