In most cases, the cause of scoliosis is unknown and it cannot usually be prevented.
The condition is not thought to be linked with things like bad posture, exercise or diet.
Unknown cause
If the cause of scoliosis is unknown, it is called idiopathic scoliosis. About 8 out of every 10 cases of scoliosis are idiopathic.
However, researchers have found that in about a third of idiopathic scoliosis cases, there is some family history of the condition, which suggests a genetic link.
Idiopathic scoliosis can affect adults and children. Many cases of scoliosis in adults are thought to be milder cases of idiopathic scoliosis that have only become more severe in later life.
Other health conditions
Many cases of scoliosis are caused by conditions that affect the nerves and muscles (neuromuscular conditions), such as:
- cerebral palsy – a condition caused by brain damage that occurs during birth or shortly afterwards
- muscular dystrophy – a genetic condition that causes muscle weakness
Although rare, scoliosis can also develop as part of a pattern of symptoms called a syndrome. This is known as syndromic scoliosis. Conditions that can cause syndromic scoliosis include:
- Marfan syndrome – a disorder of the connective tissues inherited by a child from their parents
- Rett syndrome – a genetic disorder, usually affecting females, which causes severe physical and mental disability
These conditions are usually diagnosed at a young age and children with them are often monitored for problems like scoliosis.
Birth defect
In rare cases, scoliosis is present at birth. This is known as congenital scoliosis. Congenital scoliosis is caused by the bones in the spine developing abnormally in the womb.
Long-term damage
In adults, scoliosis can sometimes be cause by gradual damage to the parts of the spine. This is known as degenerative scoliosis.
Some parts of the spine are known to narrow and weaken with age, which can explain some cases of degenerative scoliosis.
Other possible causes include:
- weakening of the bones of your spine (osteoporosis); this is a common effect of the ageing process
- damage to the spine that occurred during surgery
- damage to the spinal cord that has resulted in the loss of muscle function (paralysis)
- conditions that can damage the nerves and muscles that are near to the spine, such as motor neurone disease, multiple sclerosis or Parkinson’s disease