Read about the main causes of tinnitus, including hearing loss and damage from exposure to loud noises.
It's not clear exactly what causes tinnitus, but it's thought to be a problem with how the ear hears sounds and how the brain interprets them.
Many cases are associated with hearing loss caused by damage to the inner ear, although around one person in every three with the condition doesn't have any obvious problem with their ears or hearing.
Inner ear damage
Sounds pass from the outer ear through to the inner ear, which contains the cochlea and auditory nerve. The cochlea is a coiled, spiral tube containing a large number of sensitive hair cells. The auditory nerve transmits sound signals to the brain.
If part of the cochlea is damaged, it will stop sending information to your brain. The brain may then actively "seek out" signals from parts of the cochlea that still work. These signals might then become over-represented in the brain, which may cause the sounds of tinnitus.
In older people, damage to the cochlea often occurs naturally with age. In younger people, it can be caused by repeated exposure to excessive noise.
As well as inner ear damage, there are several other possible causes of tinnitus. These include:
Less commonly, tinnitus may develop as a result of: