Tinnitus

• Ringing
• Buzzing
• Roaring
• Clicking
• Whistling
• Hissing

The phantom noise may vary in pitch from a low roar to a high squeal, and you may hear it in one or both of your ears. In some cases, the sound can be so loud it interferes with your ability to concentrate or hear. Tinnitus may be present all of the time, or it may come and go.

There are two kinds of tinnitus.

• Subjective tinnitus is tinnitus only you can hear. This is the most common type of tinnitus. It can be caused by ear problems in your outer, middle or inner ear. It can also be caused by problems with the hearing (auditory) nerves or the part of your brain that interprets nerve signals as sound.
• Objective tinnitus is tinnitus your doctor can hear when he or she does an examination. This rare type of tinnitus may be caused by a blood vessel problem, an inner ear bone condition or a muscular issue.

Causes

A number of health conditions can cause or worsen tinnitus. In many cases, an exact cause is never found.

A common cause of tinnitus is inner ear cell damage. Tiny, delicate hairs in your inner ear move in relation to the pressure of sound waves. This triggers ear cells to release an electrical signal through a nerve from your ear (auditory nerve) to your brain. Your brain interprets these signals as sound. If the hairs inside your inner ear are bent or broken, they can "leak" random electrical impulses to your brain, causing tinnitus.

Other causes of tinnitus include other ear problems, chronic health conditions, and injuries or conditions that affect your auditory nerves or the hearing center in your brain.

Common causes of tinnitus

In many people, tinnitus is caused by one of these conditions:

• Age-related hearing loss. For many people hearing begins to worsen with age, usually starting around age 60. Loss of hearing can cause tinnitus. The medical term for this type of hearing loss is presbycusis.
• Exposure to loud noise. Loud noises can damage your ability to hear. Heavy equipment, chain saws and firearms are common sources of noise-related hearing loss. Portable music devices, such as MP3 players or iPods, also can cause noise-related hearing loss if played loudly for long periods. While short-term exposure, such as attending a loud concert, usually causes tinnitus that goes away, long-term exposure to loud sound can cause permanent damage.
• Earwax blockage. Earwax protects your ear canal by trapping dirt and slowing the growth of bacteria. However, when too much earwax accumulates it becomes too hard to wash away naturally (cerumenal impaction), causing tinnitus or problems with hearing.
• Changes in ear bones. Stiffening of the bones in your middle ear (otosclerosis) may affect your hearing and cause tinnitus. This condition, caused by abnormal bone growth, runs in families.

Other causes of tinnitus

Some causes of tinnitus are less common. These include:

• Meniere's disease, an inner ear disorder. Doctors think it's caused by abnormal inner ear fluid pressure or composition.
• Stress and depression. This is an especially common diagnosis when hearing tests are normal and no other cause of tinnitus can be identified.
• Head injuries or neck injuries. These neurological disorders affect nerves or brain function linked to hearing. Head or neck injuries generally cause tinnitus in only one ear.
• Acoustic neuroma, a noncancerous (benign) tumour. Acoustic neuromas develop on the cranial nerve, which runs from your brain to your inner ear and controls balance and hearing. This condition is also called vestibular schwannoma. It generally causes tinnitus in only one ear.

Blood vessel disorders linked to tinnitus

In rare cases, tinnitus is caused by a blood vessel disorder. This type of tinnitus is called pulsatile tinnitus. Causes include:

• Head and neck tumours. A tumor that presses on blood vessels in your head or neck (vascular neoplasm) can cause tinnitus and other symptoms.
• Atherosclerosis. With age and buildup of cholesterol and other fatty deposits, major blood vessels close to your middle and inner ear lose some of their elasticity — the ability to flex or expand slightly with each heartbeat. That causes blood flow to become more forceful and sometimes more turbulent, making it easier for your ear to detect the beats. You can generally hear this type of tinnitus in both ears.
• High blood pressure. Hypertension and factors that increase blood pressure, such as stress, alcohol and caffeine, can make tinnitus more noticeable. Repositioning your head usually causes the sound to disappear.
• Turbulent blood flow. Narrowing or kinking in a neck artery (carotid artery) or vein in your neck (jugular vein) can cause turbulent blood flow, leading to tinnitus.
• Malformation of capillaries. A condition called arteriovenous malformation (AVM), which occurs in the connections between arteries and veins, can result in tinnitus. This type of tinnitus generally occurs in only one ear.

Medications that can cause tinnitus

A number of medications may cause or worsen tinnitus. Generally, the higher the dose of medication you take, the worse tinnitus becomes. Often the unwanted noise disappears when you stop using these drugs. Medications known to cause or worsen tinnitus include:

• Antibiotics, including chloramphenicol, erythromycin, tetracycline, vancomycin and bleomycin.
• Cancer medications, including mechlorethamine and vincristine.
• Diuretics — water pills — such as bumetanide, ethacrynic acid, furosemide.
• Quinine medications used for malaria or other health conditions.
• Chloroquine, a malaria medication.
• Aspirin taken in uncommonly high doses (12 or more per day) may cause tinnitus. 

Risk factors

Anyone can get tinnitus, but you might be at increased risk if:

• You've been exposed to loud noise without ear protection, especially on an ongoing basis
• You're an older adult. Tinnitus is most common in people over 65
• You have age-related hearing loss
• You're a man
• You're Caucasian
• You have post traumatic stress disorder (PTSD). Tinnitus is especially aggravated by loud noises in people with PTSD

Complications

Tinnitus can significantly affect quality of life. It affects people differently, but may be linked to:

• Fatigue
• Stress
• Sleep problems
• Trouble concentrating
• Memory problems
• Depression
• Anxiety and irritability

Treating these linked conditions may not affect tinnitus directly, but it can help you feel better.

Diagnosis

Your doctor will examine your ears, head and neck to look for possible causes of tinnitus.

• You'll need a complete hearing (audiological) exam. This can help rule out or identify possible causes of tinnitus.
• Your doctor will check your ears to see if earwax or another problem inside your ear may be causing tinnitus symptoms. In addition, he or she will attempt to hear noise with a stethoscope over the area of your head and neck around the ears.
• Be prepared to discuss when your symptoms started, how much they bother you and whether anything makes them worse. Your doctor will want to know exactly what your tinnitus sounds like, whether it occurs in one or both ears, and if it's a steady sound or if it comes and goes.
• Your doctor may ask you to move your eyes, clench your jaw or move your neck, arms and legs. If your tinnitus changes or worsens, it may help identify an underlying disorder that needs treatment.
• Depending on the suspected cause of your tinnitus, you may need radiologic (X-ray) imaging tests such as CT or MRI scans.

The exact sounds can help your doctor identify a possible underlying cause.

• Muscle contractions around your ear can cause sharp clicking sounds that happen in bursts. They may last from several seconds to a few minutes.
• Blood vessel problems, such as high blood pressure, an aneurysm or a tumor can amplify the sound of your heartbeat in your ears (pulsatile tinnitus).
• Meniere's syndrome can cause continuous low-pitched ringing sounds in one ear. Tinnitus may become very loud before a vertigo attack (a sense that you or your surroundings are spinning or moving).
• Stiff inner ear bones (otosclerosis) can cause low-pitched tinnitus that may be continuous, or may come and go.
• Earwax, foreign bodies or hairs in the ear canal can rub against the eardrum, causing a variety of sounds.Exposure to a very loud noise or a blow to the ear can cause a high-pitched ringing or buzzing that usually goes away after a few hours. However, if there's hearing loss also, tinnitus may be permanent.
• Long-term noise exposure, age-related hearing loss or medications can cause a continuous, high-pitched ringing in both ears.Acoustic neuroma can cause continuous, high-pitched ringing in one ear. After a few years, it can also cause hearing loss or distortion.
• In many cases, the cause of tinnitus is never found. Your doctor can discuss with you steps you can take every day to reduce the severity of your tinnitus or help you cope better with the noise.

References

https://www.hse.ie/eng/health/az/T/Tinnitus/Treating-tinnitus.html

http://www.nhs.uk/conditions/tinnitus/Pages/Introduction.aspx

http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(13)60142-7/abstract

http://www.bmj.com/content/348/bmj.g216