First of all it is important to understand that tinnitus is not a disease.
It is a condition wherein the person suffering from it hears sounds in the ear or head which are not present in the surrounding environment.
The sound varies from ringing to buzzing to swishing to humming.
In most cases of tinnitus, the sound does not cause a serious problem.
Rather it is a nuisance.
In the United States nearly 50 million people suffer from tinnitus according to the American Tinnitus Association.
What cases tinnitus? Tinnitus can occur in any of the four sections of the ear -- the outer ear, middle ear, inner ear and the brain.
Some tinnitus is considered to be normal.
For instance, if you enter a sound proof room, the normal outside noise is no longer present.
In this case, you will immediately become aware of head sounds in your ear.
Under normal circumstance, we do not hear the head sounds because the noises from outside block them.
Even ear wax or a foreign body in the external ear is responsible for blocking out background noises and making us more aware of the head sounds.
Fluid, infection of disease of the middle ear bone or ear drum also can cause tinnitus.
However, it has been seen that one of the most common causes of tinnitus is damage to the endings of the hearing nerve in the inner ear.
This can happen due to exposure to loud noises like hearing high intensity music, being around firearms or loud explosions.
Even advancing age can cause a certain amount of damage to the nerve.
Some medicines like aspirin, which are known as ototoxic drugs, can cause tinnitus.
Though seen rarely, but tinnitus can also be caused by a tumor in the inner ear.
This tumor is usually called an acoustic tumor.
At present there is no cure for tinnitus.