Tinnitus is hearing of certain noises in the ear in absence of any related sound outside.
Ringing, swishing or other types of noises possibly will be heard originating from head.
Tinnitus is normal sometimes, but seriousness of it may lead to permanent hearing disability.
Causes of Tinnitus There are four sections of the ear: the outer ear, the middle ear, the inner ear and the brain.
Tinnitus can arise in any of these four sections.
It may be a symptom of variety of ear disorders or other medical conditions.
Even for doctors it is difficult to determine the exact cause of tinnitus.
Tinnitus can be hereditary because of few rare inherited inner ear disorders like neurofibromatosis.
However, that is a rare case with it and cannot be always called inherited as a genetic trait.
The other reasons for the cause of tinnitus may include:

1. Building of wax or any foreign body in any part of ear
2. Hypertension or high blood pressure
3. Fluid, infection or disease to middle ear bones or ear drum
4. Any head injury
5. Getting hearing loss or other hearing problems due to advanced age
6. Anemia
7. Damage to the microscopic endings of the hearing nerve in the inner ear
8. Exposure to loud noises, firearms, high intense music, etc
9. Trauma or injury resulting from blast or explosion
10. Blocking of ear canal
11. Infection to any part of ear
12. Damage caused by certain medications and antibiotics
13. Otosclerosis, a kind of middle ear disorder characterized by stiffness of the tiny bones of the ear.
    
14. Temporomandibular joint syndrome is a symptom of infection to head, jaw and face causing tinnitus.
    
15. Meniere's disease, a type of disorder of the flow of fluids of the inner ear.
    

If you are suffering from tinnitus then you need to check for quick remedies over it.
There are certain alternative remedies available but what successfully works are natural remedies without any fear for side effects.