Causes of deafness

There are many reasons why a child can be born deaf or become deaf early in life. It is not always possible to identify the reason. This section lists many of the common reasons. There is information on possible causes that happen before a child is born and those that happen at birth or afterwards.

Causes before birth (pre-natal causes)
Many children are born deaf because of a genetic reason. Deafness can be passed down in families even though there appears to be no family history of deafness. Sometimes the gene involved may cause additional disabilities or health problems.

Deafness can also be caused by complications during pregnancy. Illnesses such as rubella, cytomegalovirus (CMV), toxoplasmosis and herpes can cause a child to be born deaf. There is also a range of medicines, known as ototoxic drugs, which can damage the hearing system of a baby before birth.


Causes in infancy (post-natal causes)
As with pre-natal causes there are a number of reasons why a child may become deaf after they are born. Being born prematurely can increase the risk of being deaf or becoming deaf. Premature babies are often more prone to infections that can cause deafness. They may also be born with severe jaundice or experience a lack of oxygen at some point. Both of these can cause deafness.

In early childhood there is a range of things that can be responsible for a child becoming deaf. Infections like meningitis, measles and mumps can cause deafness. Ototoxic drugs, used to treat other types of infections in babies, can also be a cause.

Occasionally deafness is caused by an injury to the head or exposure to loud noise. These can cause damage to the hearing system.
Namibian child © Jon Spaull